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Physical conditioning effects on fetal heart rate responses to graded maternal exercise
Abstract
This study examined the effects of advancing gestational age and maternal aerobic conditioning (stationary cycling) on fetal heart rate (FHR) responses to strenuous non-steady-state maternal exercise.
Subjects chose to participate in either an exercise group (EG) or control group (CG). Fourteen healthy, previously sedentary pregnant women participated in the exercise group, and six pregnant controls remained sedentary. Stationary cycling (heart rate target: 145 beats x min(-1)) was performed 3 d x wk(-1) by the exercised group. Exercise duration was increased from 14 to 25 min x session(-1) during the second trimester and was maintained at 25 min x session(-1) throughout the third trimester. FHR was monitored before, during, and after a progressive submaximal cycle ergometer test (peak heart rate = 170 beats x min(-1)) performed at approximately 27 and 37 wk gestation.
Mean FHR increased significantly (P < 0.05) during exercise, followed by a modest suppression and then a delayed rise during the recovery period at both observation times. Fetal bradycardia was not observed in any of the exercise tests. Effects of advancing gestational age included a lower FHR baseline both at rest and in response to maternal exercise and a lower incidence of exercise-induced tachycardia. Maternal physical conditioning did not significantly alter FHR response to maternal exercise.
Our results support the hypothesis that FHR responses to strenuous exercise are altered by advancing gestational age and a brief progressive exercise test terminated at a maternal heart rate of 170 beats x min(-1) does not induce fetal distress during a healthy pregnancy.
... Test length is short enough for all participants to complete, but long enough to produce maternal and fetal physiological responses (Brenner, Wolfe, Monga, & McGrath, 1999;Rafla & Cook, 1999). At 34-36 weeks of gestation, the fetal heart and circulatory system have completed structural changes making heartbeat recordings easier (Sadler, 2010). ...
... Nevertheless, this FHR response could be also due to a flat or reduce response to the FHR. One research has been found with a similar exercise intervention to the one presented in our study (Brenner et al., 1999), which ease results comparison. Authors in this research found that FHR at rest and post maternal effort was not different in fetuses of women who exercise. ...
... Furthermore, this research shows an increase in FHR during maternal exercise, voiding the possibility of a flat response of FHR in these fetuses. To confirm an approximate response of FHR in our study to the FHR response found by Brenner et al. (1999) FHR during maternal exercise should have been evaluated. Nevertheless, we have been unable to provide that analysis due to recurrent signal loss in FHR recordings during both walking tests. ...
This study aims to determine if regular maternal physical exercise leads to measurable adaptations of the fetal autonomic nervous system (fANS) tested by fetal heart rate recovery time. A randomized controlled trial enrolled 131 pregnant women into two study groups, Exercise Group (EG) and Control Group (CG). All participants signed an informed consent, study was approved by the local Clinical Research Ethics Committee. Data was analyzed on 81 participants. EG participants (n = 43) received a supervised physical exercise program (PEP) three times a week from 10–12 to 36–40 weeks gestation. CG participants (n = 38) did not receive any supervised PEP. All women were tested between 34–36 weeks gestation using two walking tests of three minutes each at 40% and 60% maternal heart rate reserve. Resting fetal heart rate (FHR), FHR post-maternal exercise, and fetal recovery time (FRT) in minutes/seconds (m/s) were recorded. Resting FHR was similar between groups 140.88 ± 9 EG vs 141.95 ± 7.35 CG (p > .05). Difference in resting to post-maternal exercise FHR was statistically significant in fetuses from the CG (p < .05), however was not statistically significant in fetuses from the EG (p > .05). FRT was different between groups after both tests: 40% test: 2m15s ± 3m19s EG vs 7m6s ± 5m28s CG (p < .001); 60% test: 3m ± 4m3s EG vs 9m25s ± 7m33s CG (p < .001). There were no significant differences in maternal variables (p > .05), except for maternal recovery time after 40% test (p < .05). Influence of maternal exercise in FHR response still remains unclear. Further research is needed to elicit a former conclusion on the effects of maternal exercise on fANS. Overall, exercise during pregnancy is safe and not harmful for the cardiovascular system of the fetus.
... Resting FHR ranged from 138.0 to 157.4 bpm in the second trimester across 20 studies (n=581 women). 22 Fetal heart rate response during acute exercise ...
... There was 'very low' to 'moderate' quality evidence showing no between-group difference or lower resting FHR in women who were active throughout pregnancy (i.e., habitually active) compared with women who were not (see online supplement additional results and figures [15][16][17][18][19][20][21][22][23]. Tests for subgroup analysis were not significant. ...
... 22 23 25-27 42-47 56 68 75-79 The quality of evidence was downgraded from 'low' to 'very low' due to serious inconsistency. Fifteen studies were included in the pooled analysis (n=291 women) and showed a mean increase in FHR of 6.35 bpm during acute exercise (95% CI 2.30 to 10.41, I 2 =95%, p=0.002,figure 2).1 22 23 25 26 42-47 56 68 75 77 A post hoc sensitivity analysis was performed removing one trial (n=6 women) demonstrating a decrease in FHR of 58 bpm during exercise 1 ; ...
Objective
To perform a systematic review and meta-analysis examining the influence of acute and chronic prenatal exercise on fetal heart rate (FHR) and umbilical and uterine blood flow metrics.
Design
Systematic review with random-effects meta-analysis and meta-regression.
Data sources
Online databases were searched up to 6 January 2017.
Study eligibility criteria
Studies of all designs were included (except case studies) if published in English, Spanish or French, and contained information on the population (pregnant women without contraindication to exercise), intervention (subjective or objective measures of frequency, intensity, duration, volume or type of exercise, alone [“exercise-only”] or in combination with other intervention components [eg, dietary; “exercise + co-intervention”]), comparator (no exercise or different frequency, intensity, duration, volume and type of exercise) and outcomes (FHR, beats per minute (bpm); uterine and umbilical blood flow metrics (systolic:diastolic (S/D) ratio; Pulsatility Index (PI); Resistance Index (RI); blood flow, mL/min; and blood velocity, cm/s)).
Results
‘Very low’ to ‘moderate’ quality evidence from 91 unique studies (n=4641 women) were included. Overall, FHR increased during (mean difference (MD)=6.35bpm; 95% CI 2.30 to 10.41, I ² =95%, p=0.002) and following acute exercise (MD=4.05; 95% CI 2.98 to 5.12, I ² =83%, p<0.00001). The incidence of fetal bradycardia was low at rest and unchanged with acute exercise. There were no significant changes in umbilical or uterine S/D, PI, RI, blood flow or blood velocity during or following acute exercise sessions. Chronic exercise decreased resting FHR and the umbilical artery S/D, PI and RI at rest.
Conclusion
Acute and chronic prenatal exercise do not adversely impact FHR or uteroplacental blood flow metrics.
... Test length is short enough for all participants to complete, but long enough to produce maternal and fetal physiological responses (Brenner, Wolfe, Monga, & McGrath, 1999;Rafla & Cook, 1999). At 34-36 weeks of gestation, the fetal heart and circulatory system have completed structural changes making heartbeat recordings easier (Sadler, 2010). ...
... Nevertheless, this FHR response could be also due to a flat or reduce response to the FHR. One research has been found with a similar exercise intervention to the one presented in our study (Brenner et al., 1999), which ease results comparison. Authors in this research found that FHR at rest and post maternal effort was not different in fetuses of women who exercise. ...
... Furthermore, this research shows an increase in FHR during maternal exercise, voiding the possibility of a flat response of FHR in these fetuses. To confirm an approximate response of FHR in our study to the FHR response found by Brenner et al. (1999) FHR during maternal exercise should have been evaluated. Nevertheless, we have been unable to provide that analysis due to recurrent signal loss in FHR recordings during both walking tests. ...
INTRODUCTION
Aerobic exercise influences cardiac autonomic nervous system (ANS) function in adults, seen as lower resting heart rate and heart rate recovery post-exercise (1). Intrauterine life could be affected by maternal habits during pregnancy (2). Recent research has reported improved ANS function in fetuses of active pregnant women (3,4). The aim of this study is to evaluate fetal heart adaptations due to enhancement of the fetal ANS as a result of maternal exercise.
METHODS
A randomized controlled trial (ID: RCT, NCT01723293) enrolled 81 pregnant women in two study groups. All participants signed an informed consent. The study was approved by the Clinical Research Ethics Committee University Hospital of Fuenlabrada (Madrid).
The exercise group (EG n=43) received a supervised physical activity program(PAP) three times a week from 9-11 to 37-39 weeks gestation (5). The control group (CG n=38) did not receive any supervised PAP. All women were tested between 34-36 weeks gestation using two walking tests of three minutes each: 40% maternal heart rate reserve(MHRR) and 60% MHRR (4). Fetal heart rate (FHR) at rest and fetal recovery time (FRT) post-exercise in minutes/seconds (m/s) were recorded.
RESULTS
FHR at rest was similar in both groups 140,88±9 EG vs 141,95±7,35 CG (p>,05). FRT after 40% test was: 2m15s±3m2s EG vs 7m6s±5m27s CG (p<,001). FRT after 60% test was: 3m±4m EG vs 9m 25s±7m33s CG (p<,001).
DISCUSSION
Results show a faster recovery in fetuses of participants in EG, which could be an effect of the PAP performed during pregnancy (3). These fetuses received a training effect similar to that seen in trained adults. Further research in this field should be carried out to discover more evidence about the influence of exercise on fetal ANS development and its possible maintenance in the newborn´s life.
1. Heffernan K, Fahs C, Shinsako K, Jae S, Fernhall B. Heart rate recovery and heart rate complexity following resistance exercise training and detraining in young men. Am J Physiol Heart Circ Physiol. 2007;293:H3180–6.
2. Barker DJ. Fetal origins of coronary heart disease. BMJ. 1995;311(6998):171–4.
3. May L, Glaros A, Yeh H-W, Clapp J, Gustafson K. Aerobic exercise during pregnancy influences fetal cardiac autonomic control of heart rate and heart rate variability. Early Hum Dev. 2010 Apr;86(4):213–7.
4. Roldan O, Perales M, Mateos S, Barakat R. Supervised physical activity during pregnancy improves fetal cardiac response. Rev int med cienc act fis dep. 2015;15(60):757–72.
5. ACOG. ACOG committee opinion. Exercise during pregnancy and the postpartum period. Number 267, January 2002. American College of Obstetricians and Gynecologists. IntJ Gynaecol Obs. 2002;77(1):79–81.
... Physical exercise program Physical exercise program design was based on the Guidelines of American College of Obstetricians and Gynecologist (20) , since they are basic and safe lines of actuation supported by several researches (4,9,18,21,22) . That reassures fetal and maternal well-being during and after physical activity. ...
... Several authors studied FHR response to maternal exercise (21,22,(31)(32)(33)(34)(35)(36)(37)(38) ; nevertheless, the controversy about the adaptation of this parameter is still maintained (16) . ...
... Their results show no significant differences in FHR at rest between groups, nor in recovery time (10-20 minutes). They indicate a decrease of FHR immediately after exercise, but without significant differences from the statistical viewpoint (22) . ...
... Other studies demonstrate the fetal cardiovascular system (i.e., fetal heart rate) responds either during or immediately after maternal exercise, but did not exceed normal limits (16,104,182,204). Fetal heart rate, for instance, increases during maternal exercise (42,64,104,122,224). After this initial response to the acute physiological stress of maternal exercise, fetal heart rate returns to baseline levels within 30 min or less (42,64,104,122,224). ...
... Fetal heart rate, for instance, increases during maternal exercise (42,64,104,122,224). After this initial response to the acute physiological stress of maternal exercise, fetal heart rate returns to baseline levels within 30 min or less (42,64,104,122,224). Additionally, a significant difference in heart-rate variability was noted between preand postexercise measures. ...
... These findings portray a fetal response to maternal exercise, but not fetal distress. Regardless of fitness level prior to conception, the majority of studies found an acute bout of maternal aerobic exercise elicits an increased fetal heartrate response (42,64,67,70,104,122,182,225) The evidence overwhelming shows that maternal aerobic exercise of moderate or vigorous intensity is tolerated by the fetus and does not have adverse fetal cardiovascular effects (104). Thus far there has been no association with fetal distress and maternal exercise (59,104). ...
Although the physiology of the heart and vascular system has not changed, there are many things we have learned and are still learning today. Research related to heart adaptations during pregnancy has been performed since the 1930s. Since the mid-1950s, researchers began to look at changes in the maternal cardiovascular system during exercise while pregnant. Research related to exercise during pregnancy and offspring heart development began and has continued since the 1970s. We will review the normal female cardiovascular system adaptations to pregnancy in general. Additionally, topics related to maternal cardiac adaptations to pregnancy during acute exercise, as well as the chronic conditioning response from exercise training will be explored. Since physical activity during pregnancy influences fetal development, the fetal cardiac development will be discussed in regards to acute and chronic maternal exercise. Similarly, the influence of various types of maternal exercise on acute and chronic fetal heart responses will be described. Briefly, the topics related to how and if there is maternal-fetal synchrony will be explained. Lastly, the developmental changes of the fetal cardiovascular system that persist after birth will be explored. Overall, the article will discuss maternal cardiac physiology related to changes with normal pregnancy, and exercise during pregnancy, as well as fetal cardiac physiology related to changes with normal development, and exercise during pregnancy as well as developmental changes in offspring after birth. © 2015 American Physiological Society. Compr Physiol 5:1325-1344, 2015.
... El diseño de este programa de ejercicio físico se apoyó en las Líneas Directrices del Colegio Americano de Ginecólogos y Obstetras (20), ya que se trata de unas líneas de actuación básicas y seguras mantenidas por casi la totalidad de los trabajos de investigación consultados (4,9,18,21,22). Asegurando el bienestar materno-fetal durante y después de la actividad física. ...
... Existen una importante cantidad de estudios que se ocupan del comportamiento de la FCF como respuesta al ejercicio materno (21,22,(31)(32)(33)(34)(35)(36)(37)(38). Aunque la gran variabilidad de diseño entre ellos hace que exista cierta controversia en cuanto al comportamiento de éste parámetro (16). ...
... Sus resultados no muestran diferencias significativas en la FCF en reposo entre grupos (GC y GE), tampoco en el tiempo de recuperación (10-20 minutos). Señalan un pequeño descenso de la FCF inmediatamente después del ejercicio, pero sin diferencias significativas (22). ...
ABSTRACT
Objective: To assess the influence of a physical activity program during pregnancy on the adaptation of the fetal heart rate (FHR). Greater adaptations and faster recovery are expected to find.
Methods: 45 pregnant women included in a randomized control trial, all with uncomplicated pregnancies for exercise were studied in their third trimester of pregnancy. Rest FHR, post-exercise FHR and recovery time were assessed.
Results: Rest FHR was similar in both groups. Post-exercise FHR were significantly higher in control group (CG) than in exercise group (EG) in both test, 40% 138,5±6,4EG vs 141±7,5CG (p=0,001), 60% 141,6±10,8EG vs 150,3±16,8CG. The same was found in recovery time, 40% 78,2±95,7EG vs 328,4±315,2CG (p=0,001), al 60% 193,3±257,8EG vs 542,6±482,9CG (p=0,003).
Conclusion: Greater adaptation in post-exercise FHR and faster recovery to rest FHR have been found as a result of a physical activity program carried out during pregnancy.
Keywords
Pregnancy, exercise, fetal heart rate, recovery time.
... This is followed by a gradual return to baseline post-exercise . Fetal heart rate acceleration is accepted as a sign of well-being (Webb et al., 1994), while a decline in FHR below normal values (bradycardia) is more alarming, indicating insufficient oxygen (Brenner et al. 1999). Incidence of fetal bradycardia has been reported sporadically, although it has generally been found in untrained women exercising at maximal bouts (Pivarnik et al., 1991;Watson et al., 1991;Webb et al., 1994). ...
... While there have been some reports that maternal exercise prevents excessive weight gain during pregnancy ), Lokey's 1991 meta-analysis showed no difference in maternal weight gain between exercising and sedentary gravidae (Lokey et al., 1991). Since 1991, most other studies have confirmed findings by Lokey (Hatch et al., 1993;Bell et al., 1995;Brenner et al., 1999;Marquez-Sterling, et al., 2000, Magann et al., 2002. Furthermore, one recent study showed no difference in maternal weight gain between gravidae exercising at high versus medium volumes (Kardel, 2005). ...
... Lokey's meta-analysis (1991) of the studies that examined the training effect of exercise during pregnancy prior to 1989 showed that maternal exercise has no effect on birthweight. Subsequently, studies by Rice and Fort (1991), Clapp and Risk (1992), Webb et al. (1994), Bell et al. (1995), Sternfeld et al. (1995), Brenner et al. (1999), and Marquez-Sterling et al. (2000) all found that maternal exercise does not affect birthweight. However, upon closer inspection, there are several inconsistencies among the studies reporting no training effect. ...
Current ACOG guidelines recommend exercise during a low-risk pregnancy for 30 minutes on most, if not all days of the week. However, little is known about how the volume of exercise performed during pregnancy affects fetoplacental size. In addition, the confounding effects of maternal nutrient intake and weight gain, and how they interact with exercise volume to influence fetoplacental size have not been appropriately addressed. Therefore, the purpose of this study was to examine the effects of varying maternal exercise volumes on neonatal birthweight and placental volume, while addressing the influence of maternal nutrient intake and weight gain. Subjects evaluated for this study included pregnant women who walked during gestation (n=26), performed non-walking aerobic exercise during gestation (n=30), or remained as sedentary controls (n=32). At 16, 20, 24, 28, 32, 36 weeks gestation, women recorded their nutrient intake for 3 consecutive days. Additionally, they kept monthly exercise logs indicating the type and duration of their exercise. Nutrient variables calculated included average daily Calorie intake, average daily carbohydrate intake, average daily protein intake, average daily fat intake, and average daily fiber intake. Exercise volume was calculated as the average number of minutes per week spent performing exercise. Latent growth modeling was the statistical procedure used to analyze how change in maternal exercise volume and nutrient intake throughout gestation affects neonatal outcomes. Neonatal outcomes measured were birthweight, corrected birthweight for gestational age, sex, race, and socioeconomic status, and placental volume at delivery. Maternal walking volume had no effect on newborn birthweight or corrected birthweight, while it was inversely related to placental size at birth. Maternal non-walking aerobic exercise volume was inversely related with newborn birthweight, while there was a trend toward an inverse relationship with corrected birthweight and placental volume. Controlling for Calorie intake strengthened the relationship between any form of exercise volume and infant birthweight. Calorie intake, carbohydrate intake, and protein intake were all positively related to infant birthweight. Fiber intake was significantly inversely related to placental volume. Finally, maternal exercise volume and nutrient intake were not related to maternal weight gain. This data suggests that neonatal outcome will be affected by variations in exercise protocol. In addition, nutrient intake is a potentially confounding variable that should be examined when undertaking studies addressing the role of maternal exercise on neonatal outcome.
... In uncomplicated pregnancies, women with or without a previously sedentary lifestyle should be encouraged to participate in aerobic and strength-conditioning exercises as part of a healthy lifestyle. 7,12,14,[19][20][21][22] (II-1,2B) Women with complicated pregnancies have been discouraged from participating in exercise activities for fear of impacting the underlying disorder or maternal or fetal outcomes. 23 The conditions listed in Table 1 represent exclusion criteria for subjects participating in research studies. ...
... 23 The conditions listed in Table 1 represent exclusion criteria for subjects participating in research studies. [19][20][21][22] Evidence specifically detailing the risks of exercise in pregnancy for women with these conditions is not available (III-C). "Relative contraindications" refers to conditions in which risks may exceed benefits of regular physical activity. ...
... 7,10-12,14 (II-1,2B) When starting an aerobic exercise program, previously sedentary women should begin with 15 minutes of continuous exercise three times a week, increasing gradually to 30-minute sessions four times a week. 19,20,[29][30][31] Episodic maximal exercise by pregnant women in a research setting appears ...
Objective: To design Canadian guidelines advising obstetric care providers of the maternal, fetal, and neonatal implications of aerobic and strength-conditioning exercises in pregnancy. Outcomes: Knowledge of the impact of exercise on maternal, fetal, and neonatal morbidity, and of the maternal measures of fitness. Evidence: MEDLINE search from 1966 to 2002 for English- language articles related to studies of maternal aerobic and strength conditioning in a previously sedentary population, maternal aerobic and strength conditioning in a previously active population, impact of aerobic and strength conditioning on early and late pregnancy outcomes, and impact of aerobic and strength conditioning on neonatal outcomes, as well as for review articles and meta-analyses related to exercise in pregnancy.
... Aerobic exercise [5,7,9,[11][12][13]15,21,24,27,28,34], progressive resistive strengthening [8,10,17,23,25,27,32], stretching exercises [36,37], yoga [6,30], and Qi [20] have all been reported to be safe to perform when pregnant. The type of aerobic exercise that has been found to be beneficial during pregnancy is quite varied. ...
... An aerobic exercise prescription of 60 minutes or longer has been found to be safe for mother, fetus, and infant [14,19,23,26,30,[32][33][34]36]. The intensity of aerobic exercise can be safely monitored by using self-pacing techniques [27,28] or heart rate monitoring using 50%-75% of the age-predicted maximum [11,25,28,32]. The safe use of progressive resistive strength training in pregnancy has been reported in only a few studies [8,10,17]. ...
... Maternal benefits from exercise during pregnancy include improved cardiovascular function [11,24,25,29,[42][43][44][45], a lower risk for gestational diabetes in women who are obese or not obese [17,[46][47][48], improved strength [28] and lean muscle mass [8], improved sense of well-being [7,20,26,28,30,34], and enhanced sleep [6,49]. In addition, reductions in bone density loss [50] and physical discomfort [5][6][7]31] have been reported. ...
There is a direct link between healthy mothers and healthy infants. Exercise and appropriate nutrition are important contributors to maternal physical and psychological health. The benefits and potential risks of exercise during pregnancy have gained even more attention, with a number of studies having been published after the 2002 American College of Obstetrics and Gynecologists guidelines. A review of the literature was conducted by using PubMed, Scopus, and Embase to assess the literature regarding the benefits of exercise during pregnancy. The search revealed 219 publications, which the authors then narrowed to 125 publications. The purpose of this review is to briefly summarize the known benefits of exercise to the mother, fetus, and newborn.
... Therefore, for women under 20 years of age, a heart rate (HR) between 140 and 155 bpm is recommended ; for women 20-29 years of age, HR should remain between 135 and 150 bpm; from 30 to 39 years of age, HR should remain between 130 and 145 bpm; and for women >40 years of age, HR should be between 125 and 140 bpm [5]. The effect of the regular practice of physical exercise during pregnancy on fetal heart activity and its vitality has not yet been studied in depth, although some studies have shown the relationship between maternal physical activity and the physiological responses of increased fetal heart rate678. Few studies have been carried out in pregnant women in water and many questions remain to be answered on this subject, although no harmful effect of this practice on the fetus has been reported [1]. ...
... This parameter has not been evaluated systematically in the studies that have been published on pregnant women exercising in water; however, this trend has been reported previously in pregnant women carrying out physical exercise on bicycles [7] . Nevertheless , most of the studies evaluating the number of accelerations have reported little or no influence of the practice of physical activity by pregnant women on this variable [7,16,17,19], and rarely any reduction in the number of accelerations following exercise [22]. Anyway, we think that is worth to know that some low riskTable 3 Proportion of alteration in the ratio between fetal movements and accelerations (FM/A) and the presence of decelerations recorded by cardiotocography (CTG) prior to and following moderate physical exercise in water, according to gestational age pregnant women can show an altered ratio between fetal body movements and accelerations with no pathological meaning. ...
... These results were rather unexpected. Although this variable has not yet been comprehensively studied in physical activity in water, studies using land-based exercise have shown an absence of association between variability in FHR and maternal physical activity [7], or even an increase in the proportion of cases in which a reduction was recorded following exercise [16,22]. The altered FM/A ratio, as well as spontaneous decelerations , were infrequent and did not differ significantly between pre-water aerobic measurements and post-exercise measurements. ...
To evaluate the effect of moderate aerobic physical activity in water on fetal cardiotocography patterns in sedentary pregnant women.
In a non-randomized controlled trial, 133 previously sedentary pregnant women participated in multiple regular sessions of water aerobics in a heated swimming pool. Cardiotocography was performed for 20 minutes before and just after the oriented exercise. Cardiotocography patterns were analyzed pre- and post-exercise according to gestational age groups (24-27, 28-31, 32-35 and 36-40 weeks). Student's t and Wilcoxon, and McNemar tests were used, respectively, to analyze numerical and categorical variables.
No significant variations were found between pre- and post-exercise values of fetal heart rate (FHR), number of fetal body movements (FM) or accelerations (A), FM/A ratio or the presence of decelerations. Variability in FHR was significantly higher following exercise only in pregnancies of 24-27 weeks.
Moderate physical activity in water was not associated with any significant alterations in fetal cardiotocography patterns, which suggests no adverse effect on the fetus.
... One of the postulated mechanisms underlying the change in fetal breathing movement following maternal exercise is mild fetal hypoxia [12]. Such mild hypoxia is consistent with the transient increase in fetal HR that is reported immediately after exercise [25,5,2]; however, the accuracy of this speculated mechanism has yet to be determined [40]. Another possible mechanism is the rise in maternal norepinephrine during exercise, which could cross the placenta [26] and decrease fetal breathing frequency [28,18]. ...
... Based on the broader literature on exercise during pregnancy, moderate maternal exercise does not seem to deleteriously affect the fetus [3,5,33]. The usefulness of monitoring fetal body and breathing movement during and following maternal exercise has yet to be determined. ...
... INTRODUCTION Regular physical activity during pregnancy has many health benefits for both mother and fetus [1][2][3]. For the mother, benefits may include weight control [4] and reduced risk of early delivery and gestational diabetes [2,3,[5][6][7], and for the fetus, benefits may include improved stress tolerance and a decrease in resting fetal heart rate [8][9][10][11][12]. Despite these benefits, only 15.8 % of pregnant women (as compared to 26 % of non-pregnant women) achieve recommendations for physical activity [6,13,14] (i.e., meeting physical activity recommendations of 150 min of moderate intensity activity per week) [15][16][17]. ...
... Specifically, the intervention designed from the formative research reported here can be used to inform how physical activity messaging is incorporated into Text4baby in the future. The current Text4baby curriculum has limited SMS about physical activity, and because the evidence supporting participation in physical activity as part of a healthy pregnancy is ample [1][2][3][4][5][6][7][8][9][10][11][12], there is a need to modify standard Text4baby physical activity SMS in light of these findings. ...
Text4baby is a free, mobile health information service for pregnant and post-partum women. This study aims to understand preferences of physical activity text messages (SMS), sequentially develop prototype SMS, and determine preferred dose of SMS to inform a future study utilizing Text4baby. This study had a user-centered design with three phases: (1) literature review and interviews with pregnant women for development of prototype SMS, (2) interviews with health care professionals and pregnant women for prototype SMS feedback, and (3) survey to determine preferred dose of SMS. Data from interviews identified knowledge and support as major themes. Prototypes were developed (N = 14) and informed 168 SMS. Pregnant women (N = 326) thought three SMS/week were about right (50.2 %) and preferred three SMS/week throughout pregnancy (71.9 %). There is a need for opportunities for behavioral scientists to incorporate evidence-based practices within scalable interventions. As such, this research will inform utilization of Text4baby to potentially improve physical activity participation.
... We will discuss the effects of prenatal stress and malnutrition (over and under nutrition) on perin-atal programming of the neuroendocrine stress response (hypothalamic-pituitary-adrenal [HPA] axis), stress-sensitive brain regions and immune system and how this might influence neurodevelopment (Jansson and Powell, 2007;Lupien et al., 2009;Palmer, 2011;PrabhuDas et al., 2011;Breton, 2013;O'Connor et al., 2013;Reynold, 2013;Lin and Wang, 2014;Rook et al., in press). We will also discuss the main maternal health benefits of physical activity during pregnancy (Pivarnik et al., 1993;Genest et al., 2012;Prather et al., 2012;Robledo-Colonia et al., 2012;Ruchat et al., 2012), as well as its impact on the fetus and infant (e.g., reduced fat mass and short-term neurodevelopment benefits) (Brenner et al., 1993;Clapp, 1996;Clapp et al., 1998;San Juan Dertkigil et al., 2007;May et al., 2012;Prather et al., 2012). Although regular physical activity/exercise has been shown to promote neuroplasticity Cotman et al., 2007;Knaepen et al., 2010;Hayes et al., 2013) and an anti-inflammatory state (Gleeson et al., 2011;Hamer et al., 2012;Hayes, Hayes et al. 2013) in the adult, there is a paucity of studies evaluating its impact on the CNS and immune system during pregnancy. ...
... Benefits of maternal exercise during pregnancy for the fetus include improving cardio-vascular function (Brenner et al., 1993;May et al., 2010May et al., , 2012Gustafson et al., 2012) reduced risk of hyperglycaemia, hyperbilirubinaemia, and microsomal Hedderson et al., 2006;Stotland et al., 2006, improved viability of the placenta and amniotic fluid levels (Clapp, 2002:265;Siega-Riz et al., 2009;San Juan Dertkigil et al., 2007). In addition, the benefit for the fetus can be even greater, as there can be direct and/or indirect consequences of improved maternal general and psychological health, as described above. ...
... We will discuss the effects of prenatal stress and malnutrition (over and under nutrition) on perin-atal programming of the neuroendocrine stress response (hypothalamic-pituitary-adrenal [HPA] axis), stress-sensitive brain regions and immune system and how this might influence neurodevelopment (Jansson and Powell, 2007;Lupien et al., 2009;Palmer, 2011;PrabhuDas et al., 2011;Breton, 2013;O'Connor et al., 2013;Reynold, 2013;Lin and Wang, 2014;Rook et al., in press). We will also discuss the main maternal health benefits of physical activity during pregnancy (Pivarnik et al., 1993;Genest et al., 2012;Prather et al., 2012;Robledo-Colonia et al., 2012;Ruchat et al., 2012), as well as its impact on the fetus and infant (e.g., reduced fat mass and short-term neurodevelopment benefits) (Brenner et al., 1993;Clapp, 1996;Clapp et al., 1998;San Juan Dertkigil et al., 2007;May et al., 2012;Prather et al., 2012). Although regular physical activity/exercise has been shown to promote neuroplasticity Cotman et al., 2007;Knaepen et al., 2010;Hayes et al., 2013) and an anti-inflammatory state (Gleeson et al., 2011;Hamer et al., 2012;Hayes, Hayes et al. 2013) in the adult, there is a paucity of studies evaluating its impact on the CNS and immune system during pregnancy. ...
... Benefits of maternal exercise during pregnancy for the fetus include improving cardio-vascular function (Brenner et al., 1993;May et al., 2010May et al., , 2012Gustafson et al., 2012) reduced risk of hyperglycaemia, hyperbilirubinaemia, and microsomal Hedderson et al., 2006;Stotland et al., 2006, improved viability of the placenta and amniotic fluid levels (Clapp, 2002:265;Siega-Riz et al., 2009;San Juan Dertkigil et al., 2007). In addition, the benefit for the fetus can be even greater, as there can be direct and/or indirect consequences of improved maternal general and psychological health, as described above. ...
... We will discuss the effects of prenatal stress and malnutrition (over and undernutrition) on perin-atal programming of the neuroendocrine stress response (hypothalamic-pituitary-adrenal [HPA] axis), stress-sensitive brain regions and the immune system and how this might influence neurodevelopment (Jansson and Powell, 2007;Lupien et al., 2009;Palmer, 2011;PrabhuDas et al., 2011;Breton, 2013;O'Connor et al., 2013;Reynold, 2013;Lin and Wang, 2014;Rook et al., 2014). We will also discuss the main maternal health benefits of regular physical activity during pregnancy (Pivarnik et al., 1993;Genest et al., 2012;Prather et al., 2012;Robledo-Colonia et al., 2012;Ruchat et al., 2012), as well as its impact on the fetus and infant (e.g., reduced fat mass and short-term neurodevelopment benefits) (Brenner et al., 1993;Clapp, 1996;Clapp et al., 1998;San Juan Dertkigil et al., 2007;May et al., 2012;Prather et al., 2012). Although regular physical activity/exercise has been shown to promote neuroplasticity Cotman et al., 2007;Knaepen et al., 2010;Hayes et al., 2013) and an anti-inflammatory state (Gleeson et al., 2011;Hamer et al., 2012;Hayes, Hayes et al. 2013) in the adult, there is a paucity of studies evaluating its impact on the CNS and immune system during pregnancy. ...
... Benefits of maternal exercise during pregnancy for the fetus include improving cardiovascular function (Brenner et al., 1993;May et al., 2010May et al., , 2012Gustafson et al., 2012), reduced risk of hyperglycaemia, hyperbilirubinaemia and microsomia Hedderson et al., 2006;Stotland et al., 2006), and improved viability of the placenta and amniotic fluid levels (Clapp, et al. 2002;Siega-Riz et al., 2009;San Juan Dertkigil et al., 2007). In addition, the benefit for the fetus can be even greater, as there can be direct and/or indirect consequences of improved maternal general and psychological health, as described above. ...
... Animal studies suggest decreased uterine blood flow during physical activity [5][6][7][8], but studies in women are inconclusive [9][10][11]. Several studies have reported an increase in fetal heart rate during maternal physical activity [12][13][14][15][16], although changes in fetal heart rate may occur in response to maternal epinephrine and may not reflect a decrease in oxygen [12][13][14][15]. Physical activity has been associated with decreased maternal blood glucose during [17] or after [18][19][20][21] physical activity. ...
... Animal studies suggest decreased uterine blood flow during physical activity [5][6][7][8], but studies in women are inconclusive [9][10][11]. Several studies have reported an increase in fetal heart rate during maternal physical activity [12][13][14][15][16], although changes in fetal heart rate may occur in response to maternal epinephrine and may not reflect a decrease in oxygen [12][13][14][15]. Physical activity has been associated with decreased maternal blood glucose during [17] or after [18][19][20][21] physical activity. ...
Unlabelled:
Current US pregnancy-related physical activity recommendations do not provide specific guidance for vigorous intensity activity. We examined the associations between vigorous physical activity during pregnancy and length of gestation and birthweight.
Methods:
Women were recruited before 10 weeks gestation. At 13-16 weeks gestation, participants reported the type, frequency, and duration of their typical weekly vigorous physical activities. Activity domains included recreational, occupational, household, and child/adult care. Infant birth date was obtained from medical or vital records; if unavailable, self-report was used. Birthweight (from vital records) was studied among term births. We analyzed gestational age among 1,647 births using discrete-time survival analysis. We used logistic and linear regression to analyze preterm birth (birth at <37 weeks) and birthweight, respectively. Vigorous recreational activity was associated with longer gestation (any vs. none, hazard ratio (HR) [95% CI]: 0.85 [0.70, 1.05]) and we did not detect any dose-response association. Higher frequency of vigorous recreational activity sessions (adjusted for total volume of activity) was associated with a decreased odds of preterm birth (≥ 4 sessions/week vs. 0 or 1, OR [95% CI]: 0.08 (0.006, 1.0). Birthweight was not associated with physical activity measures. In summary, vigorous physical activity does not appear to be detrimental to the timing of birth or birthweight. Our data support a reduced risk of preterm birth with vigorous recreational activity, particularly with increased frequency of recreational activity sessions. Future studies should investigate the components of physical activity (i.e., intensity, duration, and frequency) in relation to birth outcomes.
... The results of this study present that during 27 weeks of this experiment, neither fetal hypoxia, growth retardation, placental exchange nor amniotic fluid volume abnormalities were observed in any of the fetuses, which is consistent with previous research [22][23][24]. The results of this trial are in accordance with the results of other studies, presenting that regular moderate physical activity program in pregnancy is not posing any health risks neither to the mother nor to the fetus [1,[12][13][14][15]. ...
Objectives:
The aim of this study was to evaluate the effects of a supervised physical exercise program on fetal well-being and intrauterine safety. Physical activity is recommended for healthy pregnant women. However, constant evaluation of fetal condition and development is recommended to ensure the safety of the exercise program.
Material and methods:
Randomized control trial study design. Sixty-six healthy pregnant women (age 24-35) with singleton gestation were randomly assigned to either an exercise group (EG, n = 34) or a non-active control group (CG, n = 32). The exercise program included 81 sessions (moderate intensity, 3 times per week, 50-60 min/session from weeks 13 to weeks 40/41 of pregnancy). Fetal well-being was assessed in weeks 32 and 37 of pregnancy. The cerebroplacental ratio (CPR) was calculated to evaluate the safety of the exercise program for the fetus.
Results:
The differences in the CPR ratio measurements between EG and CG groups in week 37 (p < 0.05) were observed. The increase in the CPR ratio was also shown in week 37 of pregnancy in comparison to week 32 (p < 0.01). Moreover, maternal heart rate was significantly lower in the exercise group as measured at 37 weeks (p < 0.05).
Conclusions:
The results of this study confirm that regular and supervised exercise program throughout pregnancy does not affect fetal well-being and is safe for the fetus. Additionally, regular physical activity improves maternal physical fitness and cardiac efficiency which might aid at preparing pregnant women for natural labor.
... The additional benefits of exercise include a reduction in bone density loss, reduction in physical discomfort, and improved anaerobic ventilatory threshold. 13 Benefits to the fetus include improvement in the viability of the placenta 14 and decreased resting fetal heart rate. [15][16][17] Few studies have been conducted to determine the effectiveness of stretching exercise on BP among pregnant women. ...
Background: Back pain (BP) could be present either as a pelvic girdle pain between the posterior iliac crest and the gluteal fold or as a lumbar pain over and around the lumbar spine. The management aims to reduce the discomfort and the impact on the pregnant woman’s quality of life. Purpose: The study aimed to determine the effect of back-stretch (BS) exercise on the perception of BP during pregnancy.
Design and methods: A quasi-experimental pretest-posttest control group research design was used. The study was conducted in Gottigere health center, Bangalore, Karnataka, India. The BS exercise intervention was provided to the mothers of the study group. Data were collected from 60 antenatal mothers, 30 in the study, and the control group, respectively who were in their 28-32 weeks of gestation by using a non-probability purposive sampling technique. The intensity of BP was estimated using the visual analogs scale.
Findings: The comparison between the study and control group has proved a remarkable BP reduction among the antenatal mothers after BS exercise in the study group. The post-test mean intensity of BP was lesser than the pre-test mean intensity of BP (48.73< 54.83) among mothers of the study group (P≤0.001). The antenatal mothers of the control group did not have a statistically significant reduction in the level of BP.
Conclusion: The BS exercise is effective in reducing BP among antenatal mothers during their antenatal period.
... The additional benefits of exercise include a reduction in bone density loss, reduction in physical discomfort, and improved anaerobic ventilatory threshold. 13 Benefits to the fetus include improvement in the viability of the placenta 14 and decreased resting fetal heart rate. [15][16][17] Few studies have been conducted to determine the effectiveness of stretching exercise on BP among pregnant women. ...
... 69 In the majority of the studies, the fetal responses to cycling with an increase of fHR 64 70 71 and a transient reduction after the session were followed by a delayed increase during the recovery period. 66 71 72 In a further study, the fHR increased slightly following maternal exercise but did not reach clinical implication. 73 The increase in fHR appeared to be higher during the third trimester than in the second trimester due to an increase in fetal activity. ...
Before and during pregnancy, women often aim to improve their lifestyle so as to provide a healthier environment for their developing child. It remains unresolved, however, as to whether physical activity (PA) during pregnancy poses a possible risk or whether it might even have beneficial effects on the developing child. There is increasing evidence that PA during pregnancy is indeed beneficial to maternal physiological and psychological health and that it is generally not detrimental to the fetal cardiovascular system and neuronal function in the developing child. This also led to international recommendations for PAs during pregnancy. In the current review, we aimed to comprehensively assess the evidence of beneficial and harmful effects of maternal PA, including high-performance sports, on fetal development. The different mental and body-based relaxation techniques presented here are frequently performed during pregnancy. We found a considerable number of studies addressing these issues. In general, neither low key, moderate maternal PA nor relaxation techniques were observed to have a harmful effect on the developing child. However, we identified some forms of PA which could have at least a transient unfavourable effect. Notably, the literature currently available does not provide enough evidence to enable us to make a general conclusive statement on this subject. This is due to the lack of longitudinal studies on the metabolic and cognitive effects of regular PA during pregnancy and the wide diversity of methods used. In particular, the kind of PA investigated in each study differed from study to study.
... Total enerji düzeyini etkileyen bir diğer faktör hamileliktir (Brenner, Wolfe, Monga ve McGrath, 1999). Bununla ilgili yapılan bir çalışmada 13 hamile kadının 6 haftalık gebelik sonrası dört haftada bir kalp atım sayıları ve oksijen tüketimleri bisiklet ergometresi ve koşu bandı üzerinde kontrol edilmiştir. ...
... Finally, an interaction between maternal conditioning and acute exercise was found to transiently affect fetal breathing movements and body movements. Speculated pathways include mild fetal hypoxia [11][12][13][14] as well as changes in norepinephrine concentrations [15,16]. A pictorial summary of these potential pathways is included in Fig. 1. ...
... Benefits to the foetus [100][101][102][103][104] Benefits to the foetus [ Lower heart rate response to acute maternal exercise Increased amniotic fluids Increased in placenta viability and volume Increase in vascular function Faster placental growth and greater villous tissue Higher tolerance to labour Lower birth weights Increased gestational ages (lower risk of preterm birth) Improved neurodevelopment and lower body fat percentage Infants have higher behaviour regulatory ability and orientation At the age of five children have less body fat, higher general language intelligence and oral language of this research area has focused on foetal safety during exercise [75] . There is a general agreement that appropriate exercise does not induce any harm on the foetus [75] . ...
The prevalence of gestational diabetes mellitus (GDM) is increasing worldwide. This disease has many
detrimental consequences for the woman, the unborn foetus and child. The management of GDM aims to
mediate the effects of hyperglycaemia by controlling blood glucose levels. Along with pharmacology and
dietary interventions, exercise has a powerful potential to assist with blood glucose control. Due to the
uncertainty of risks and benefits of exercise during pregnancy, women tend to avoid exercise. However,
under adequate supervision exercise is both safe and beneficial in the treatment of GDM. Therefore it is vital
that exercise is incorporated into the continuum of care for women with GDM. Medical doctors should be able
to refer to competently informed exercise professionals to aid in GDM treatment. It is important that exercise
treatment is informed by research. Hence, the development of evidence-based guidelines is important
to inform practice. Currently there are no guidelines for exercise in GDM. This review aims to assess the efficacy of exercise for the management of GDM in order to establish an exercise prescription guideline specific to the condition. It is recommended that women with gestational diabetes mellitus should do both aerobic and resistance exercise at a moderate intensity, a minimum of three times a week for 30-60 min each time.
... Benefits to the foetus [100][101][102][103][104] Benefits to the foetus [1,58,73,104,105] Lower heart rate response to acute maternal exercise Increased amniotic fluids Increased in placenta viability and volume Increase in vascular function Faster placental growth and greater villous tissue Higher tolerance to labour Lower birth weights Increased gestational ages (lower risk of preterm birth) Improved neurodevelopment and lower body fat percentage Infants have higher behaviour regulatory ability and orientation At the age of five children have less body fat, higher general language intelligence and oral language foetus [75] . However, in regards to elevate fasting glucose, aerobic exercise can indeed reduce blood glucose levels in individuals with hyperglycaemia, potentially reducing and delaying the need for insulin medication [78] . ...
The prevalence of gestational diabetes mellitus (GDM) is increasing worldwide. This disease has many detrimental consequences for the woman, the unborn foetus and child. The management of GDM aims to mediate the effects of hyperglycaemia by controlling blood glucose levels. Along with pharmacology and dietary interventions, exercise has a powerful potential to assist with blood glucose control. Due to the uncertainty of risks and benefits of exercise during pregnancy, women tend to avoid exercise. However, under adequate supervision exercise is both safe and beneficial in the treatment of GDM. Therefore it is vital that exercise is incorporated into the continuum of care for women with GDM. Medical doctors should be able to refer to competently informed exercise professionals to aid in GDM treatment. It is important that exercise treatment is informed by research. Hence, the development of evidence-based guidelines is important to inform practice. Currently there are no guidelines for exercise in GDM. This review aims to assess the efficacy of exercise for the management of GDM in order to establish an exercise prescription guideline specific to the condition. It is recommended that women with GDM should do both aerobic and resistance exercise at a moderate intensity, a minimum of three times a week for 30-60 min each time.
... Estas alterações são consistentes e independentes do período gestacional e até mesmo da intensidade do exercício realizado pela gestante. No entanto, Brenner et al. (10) recentemente demonstraram que mesmo exercícios progressivos que elevaram a FC materna a 170bpm não induziram a stress fetal durante gravidez saudável. Imediatamente e após 5 minutos de exercício a freqüência cardíaca fetal tende a permanecer significativamente elevada nas atividades físicas de intensidade leve, moderada e intensa. ...
Antes de começarmos a descrever os aspectos mais relevantes sobre a grávida que quiser praticar exercício, cremos ser importante que o médico e a paciente possam melhorar sua comunicação usando termos que expressem um mesmo fenômeno, ou em outras palavras que falem sobre a mesma coisa. Sim, porque nesta área de esportes todos pensam que sabem um pouco ou o suficiente, mas na realidade muitas das controvérsias ocorrem pela falta de conhecimento de conceitos básicos. Por exemplo, médicos e pacientes podem pensar ou usar na comunicação as expressões atividade física, exercício e esporte com um mesmo sentido. Entretanto, referem-se a expressões de movimento corporal totalmente distintos. Atividade física é qualquer movimento corporal que conseguimos realizar, em função de contração muscular e com gasto energético acima do basal. Assim, quando a mulher estiver caminhando em direção ao mercado ou dançando com seu marido ela está fazendo atividade física. É considerada a melhor relação entre movimento humano e saúde. Exercício é um tipo de atividade física mais estruturada, que envolve intensidade, freqüência, duração, tendo como objetivo melhora da apitado física e por conseguinte da saúde. Assim, quando a mulher caminhar, ao mercado ou a qualquer lugar, com um determinado número de passadas/min, para percorrer a referida distância em um determinado intervalo de tempo ela estará fazendo exercício. Esporte é um tipo de atividade física que envolve conceitos de desempenho e competição. Assim, quando a mulher quiser percorrer aquela distancia ao mercado mais rapidamente que qualquer outra, ela estará competindo, praticando esporte. O esporte pode formar alguns "vencedores" mas automaticamente muitos "perdedores", não sendo por isso a melhor mensagem de saúde pública.
... This provides little insight into the direct impact of maternal phenotype during cardiovascular development. Only a few studies have focused on early embryonic, fetal, and early postnatal cardiovascular parameters as endpoints (Brenner et al. 1999;Schwerte et al. 2005;Momoi et al. 2008;May et al. 2010May et al. , 2012Ho et al. 2011). Even so, these few studies lack the mechanistic investigation of the long-term effects of these maternally induced perinatal cardiovascular changes in the offspring. ...
Transgenerational epigenetics, the study of non-genetic transfer of information from one generation to the next, has gained much attention in the past few decades due to the fact that, in many instances, epigenetic processes outweigh direct genetic processes in the manifestation of aberrant phenotypes across several generations. Maternal effects, or the influences of maternal environment, phenotype, and/or genotype on offsprings' phenotypes, independently of the offsprings' genotypes, are a subcategory of transgenerational epigenetics. Due to the intimate role of the mother during early development in animals, there is much interest in investigating the means by which maternal effects can shape the individual. Maternal effects are responsible for cellular organization, determination of the body axis, initiation and maturation of organ systems, and physiological performance of a wide variety of species and biological systems. The cardiovascular system is the first to become functional and can significantly influence the development of other organ systems. Thus, it is important to elucidate the role of maternal effects in cardiovascular development, and to understand its impact on adult cardiovascular health. Topics to be addressed include: (1) how and when do maternal effects change the developmental trajectory of the cardiovascular system to permanently alter the adult's cardiovascular phenotype, (2) what molecular mechanisms have been associated with maternally induced cardiovascular phenotypes, and (3) what are the evolutionary implications of maternally mediated changes in cardiovascular phenotype?
... In the absence of obstetric complications, moderate exercise during pregnancy is generally considered safe and poses no known risk to the fetus [1][2][3][4][5][6][7][8]. Epidemiological data suggest that regular physical activity throughout pregnancy improves maternal cardiovascular function [3], limits weight gain and fat retention [9], improves insulin resistance and metabolic control [9][10][11], prevents the onset of gestational diabetes mellitus [12,13], reduces the incidence of operative delivery [14], and decreases depressive symptoms in the postnatal period [15,16]. ...
... There appears to be no harm in the short or long term to the fetus when a woman exercises.A group of researchers sought to monitor the cardiac responses of both fetuses and their mothers during moderate exercise.There was no evidence of distress in any of the fetuses during that study.This finding was true even with women who were sedentary before pregnancy and began an exercise program after they became pregnant. 22 No reduction was documented in the birth weight of infants whose mothers exercised moderately. 23 There is no increased incidence of neural tube defects in infants born to moderately exercising women. ...
Many pregnant women do not exercise. Exercise in pregnancy is correlated with a decrease in many common problems of pregnancy. In addition, establishing the habit of exercise in pregnancy may decrease the later life incidences of chronic hypertension and type 2 diabetes in women who are predisposed to these illnesses. Exercise during pregnancy is beneficial to fetuses as well. In most cases, there appears to be no harm to the fetus with moderate exercise. Although recommendations are currently accepted for pregnant women to engage in moderate exercise, many women may not receive this information from their health care providers. Prenatal care offers a unique opportunity to assist in the adoption of healthy behaviors.
... In the absence of obstetric complications, moderate exercise during pregnancy is generally considered safe and poses no known risk to the fetus [1][2][3][4][5][6][7][8]. Epidemiological data suggest that regular physical activity throughout pregnancy improves maternal cardiovascular function [3], limits weight gain and fat retention [9], improves insulin resistance and metabolic control [9][10][11], prevents the onset of gestational diabetes mellitus [12,13], reduces the incidence of operative delivery [14], and decreases depressive symptoms in the postnatal period [15,16]. ...
The cardiovascular benefits of exercise are well known for adults and promoted by AHA, ACSM, and the President’s Council on Physical Fitness and Sports. However, few studies have determined how exercise during pregnancy influences the cardiovascular system of mother and baby.
Magnetocardiograms (MCG) were performed during and after pregnancy to determine if exercise changes the cardiac autonomic nervous system in mother and offspring.
Findings demonstrate maternal and fetal cardiac autonomic nervous system is altered from regular exercise throughout gestation. Furthermore, the lower heart rate and increased heart rate variability seen in the fetus, persists after birth.
The cardiac autonomic measurements found in this study parallel those seen in the adult in response to exercise training. This research demonstrates that regular maternal exercise throughout pregnancy leads to cardiovascular benefits for mother and baby. Ultimately, this study suggests that exercise during gestation maintains maternal cardiovascular health and may be the earliest intervention for cardiovascular health promotion and disease prevention for the baby.
... In healthy pregnant women, regular aerobic exercise during pregnancy maintains or improves physical fitness with studies demonstrating improvements in functional aerobic capacity and cardiorespiratory capacity (25)(26)(27)(28) . Short bouts of maternal exercise are also associated with fetal physiological responses, in particular, an increase in fetal heart rate (29,30) . Whether these beneficial effects extend to obese pregnant women is not known. ...
The global pandemic of maternal obesity presents a major challenge for healthcare providers, and has significant short- and long-term implications for both maternal and fetal health. Currently, the evidence-base underpinning many of the interventions either currently in use or recommended to improve pregnancy outcome in obese women is limited. The nature and timing of these interventions vary widely, ranging from simple advice to more intensive dietary and exercise programmes, cognitive behavioural therapy and drug trials. In addition, a growing number of very severely obese women now enter pregnancy having had surgical interventions. Although surgical interventions such as gastric bypass or banding may be associated with improved pregnancy outcomes, these women have particular nutritional requirements, which need to be addressed to optimise pregnancy outcome. Until the outcomes of ongoing current trials are reported and provide a firm evidence base on which to base future intervention strategies and guide evidence based care for obese pregnant women, pregnancy outcome is best optimised by high-risk antenatal care delivered by healthcare providers who are experienced in supporting these high-risk women.
... 25,26 One report was excluded because of failure to randomise. 27 Six studies additionally performed dietary interventions, and were therefore not included. [28][29][30][31][32][33] Finally, 12 randomised controlled trials remained for the analysis. ...
high gestational weight gain (GWG) has been found to be associated with a number of adverse perinatal and long-term outcomes.
we aimed to perform a systematic review and meta-analysis to find out whether physical activity in pregnancy might help avoid high GWG.
a literature search in relevant databases and an additional search by hand through bibliographies of various publications were performed.
we included randomised controlled trials on healthy women, with increased physical activity as the only intervention. GWG had to be documented for the intervention and control group separately.
two reviewers independently extracted data and performed quality assessment. Data from the included trials were combined using a random-effects model. The effect size was expressed as mean difference (MD).
of 1380 studies identified, 12 trials met the inclusion criteria. In seven trials, GWG was lower in the exercise group compared with the control group, whereas five trials showed a lower GWG in the control groups. The meta-analysis resulted in an MD of GWG of -0.61 (95% CI: -1.17, -0.06), suggesting less GWG in the intervention groups compared with the control groups. We found no indication for publication bias or dose effects.
in summary, our analyses suggest that physical activity during pregnancy might be successful in restricting GWG.
... Some have suggested that decreased fetal HR associated with maternal exercise is due to chronic fetal hypoxia [16]. However, studies measuring uteroplacental blood flow parameters, fetal oxygenation and markers of fetal stress have determined that the fetus is not compromised during maternal exercise [15,[46][47][48][49][50][51][52][53]. Moreover, birth outcomes and neonatal morphometric measurements demonstrate maternal exercise does not have adverse effects on fetal growth and development [20,54,55]. ...
Previous studies using ultrasound technology showed that fetal heart rate (HR) may be responsive to maternal aerobic exercise. Although it is recognized that cardiac autonomic control may be influenced by the intrauterine environment, little is known about how maternal exercise affects fetal heart development.
This study tested the hypothesis that regular maternal exercise throughout gestation influences fetal cardiac autonomic control of HR and heart rate variability (HRV) when compared to fetuses of non-exercising women.
Magnetocardiograms (MCGs) were recorded using a dedicated fetal biomagnetometer at 28, 32 and 36 weeks gestational age (GA) from 26 regularly exercising (>30 min of aerobic exercise, 3x per week) and 35 healthy, non-exercising pregnant women. Fetal MCG was isolated and normal R-peaks were marked to derive fetal HR and HRV in the time and frequency domains. We applied a mixed-effects model to investigate the effects of exercise, GA and fetal activity state.
At 36 weeks GA, during the active fetal state, fetal HR was significantly lower in the exercise group (p=<0.0006). Post-hoc comparisons showed significantly increased HRV in the exercise group during the active fetal state at 36 weeks GA for both time and frequency domain measures.
These results indicate that regular maternal exercise throughout gestation results in significantly lower fetal HR and increased HRV.
Background
Regular and supervised exercise during pregnancy is worldwide recommended due to its proven benefits, but, during exercise, maternal blood flow is redirected from the viscera to the muscles and how fetal wellbeing may be affected by this redistribution is still not well known.
Objective
To analyze the longitudinal effect of a supervised moderate physical exercise program during pregnancy on uteroplacental and fetal Doppler parameters.
Methods
This is a planned secondary analysis of an randomized controlled trial (RCT), performed at Hospital Universitario de Torrejón, Madrid, Spain, including 124 women randomized from 12⁺⁰ to 15⁺⁶ weeks of gestation to exercise vs. control group. Fetal umbilical artery (UA), middle cerebral artery, and uterine artery pulsatility index (PI), were longitudinally collected by Doppler ultrasound assessment throughout gestation, and derived cerebroplacental ratio (normalized by z-score), and maternal mean PI in the uterine arteries (normalized by multiplies of the median). Obstetric appointments were scheduled at 12 (baseline, 12⁺⁰ to 13⁺⁵), 20 (19⁺⁰ to 24⁺²), 28 (26⁺³ to 31⁺³) and 35 weeks (32⁺⁶ to 38⁺⁶) of gestation. Generalized estimating equations were adjusted to assess longitudinal changes in the Doppler measurements according to the randomization group.
Results
No significant differences in the fetal or maternal Doppler measurements were found at any of the different checkup time points studied. The only variable that consistently affected the Doppler standardized values was gestational age at the time of assessment. The evolution of the UA PI z-score during the pregnancy was different in the two study groups, with a higher z-score in the exercise group at 20 weeks and a subsequent decrease until delivery while in the control group it remained stable at around zero.
Conclusions
A regular supervised moderate exercise program during pregnancy does not deteriorate fetal or maternal ultrasound Doppler parameters along the pregnancy, suggesting that the fetal well-being is not compromised by the exercise intervention. Fetal UA PI z-score decreases during pregnancy to lower levels in the exercise group compared with the control group.
Objectives
To systematically review studies evaluating one or more components of physical fitness (PF) in pregnant women, to answer two research questions: (1) What tests have been employed to assess PF in pregnant women? and (2) What is the validity and reliability of these tests and their relationship with maternal and neonatal health?
Design
A systematic review.
Data sources
PubMed and Web of Science.
Eligibility criteria
Original English or Spanish full-text articles in a group of healthy pregnant women which at least one component of PF was assessed (field based or laboratory tests).
Results
A total of 149 articles containing a sum of 191 fitness tests were included. Among the 191 fitness tests, 99 (ie, 52%) assessed cardiorespiratory fitness through 75 different protocols, 28 (15%) assessed muscular fitness through 16 different protocols, 14 (7%) assessed flexibility through 13 different protocols, 45 (24%) assessed balance through 40 different protocols, 2 assessed speed with the same protocol and 3 were multidimensional tests using one protocol. A total of 19 articles with 23 tests (13%) assessed either validity (n=4), reliability (n=6) or the relationship of PF with maternal and neonatal health (n=16).
Conclusion
Physical fitness has been assessed through a wide variety of protocols, mostly lacking validity and reliability data, and no consensus exists on the most suitable fitness tests to be performed during pregnancy.
PROSPERO registration number
CRD42018117554.
We carried a thorough systematic review of the contemporary literature regarding the impact of maternal physical activity during pregnancy on the fetal and neonatal well-being parameters. We searched systematically publications indexed in PubMed and ScienceDirect, according to the PRISMA protocol. Studies examining following fetal and neonatal well-being parameters were included: fetal heart rate, active fetal movements, Doppler assessment of the placental and fetal circulations, amniotic fluid index, Apgar score, and umbilical cord blood acid-basis analysis at delivery. Altogether, 73 studies were identified (pooled sample size n = 7,867). Out of these, 42 pertained to acute and 31 pertained to chronic exposure to maternal physical activity. The majority of the identified studies reported a positive or neutral effect of maternal physical activity on the fetal heart rate, Doppler-derived umbilical and cerebral blood flow parameters, and Apgar score. The literature regarding uterine arteries Doppler assessment, fetal active movements, amniotic fluid index, and umbilical cord blood acid-base analysis at delivery is sparse and does not allow us to generalize the inferences. Maternal physical activity during physiological pregnancy is safe for fetal and neonatal well-being when practiced according to recommendations. There is a need for better quality studies concerning the subject.
Aim
The knowledge on circadian rhythmicity is rapidly expanding. We aimed to define the longitudinal development of the circadian heart rate rhythm in the human fetus in an unrestricted, out‐of‐hospital setting, and to examine the effects of maternal physical activity, season and fetal sex.
Methods
We recruited 48 women with low‐risk singleton pregnancies. Using a portable monitor for continuous fetal electrocardiography, fetal heart rate recordings were obtained around gestational weeks 24, 28, 32 and 36. Circadian rhythmicity in fetal heart rate and fetal heart rate variation was detected by cosinor analysis; developmental trends were calculated by population‐mean cosinor and multilevel analysis.
Results
For the fetal heart rate and fetal heart rate variation, a significant circadian rhythm was present in 122/123 (99.2%) and 116/121 (95.9%) of the individual recordings, respectively. The rhythms were best described by combining cosine waves with periods of 24 and 8 hours. With increasing gestational age, the magnitude of the fetal heart rate rhythm increased, and the peak of the fetal heart rate variation rhythm shifted from a mean of 14:25 (24 weeks) to 20:52 (36 weeks). With advancing gestation, the rhythm‐adjusted mean value of the fetal heart rate decreased linearly in females (p<0.001) and non‐linearly in males (quadratic function, p=0.001). At 32 and 36 weeks, inter‐individual rhythm diversity was found in male fetuses, during higher maternal physical activity and during the summer season.
Conclusion
The dynamic development of the fetal circadian heart rate rhythm during the second half of pregnancy is modified by fetal sex, maternal physical activity and season.
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Μια από τις σημαντικότερες περιόδους στη ζωή μιας γυναίκας, είναι η περίοδος της εγκυμοσύνης της. Είναι, πολύ σημαντικό να καταφέρει μια γυναίκα να περάσει τους εννέα αυτούς μήνες όσο πιο ανώδυνα γίνεται και να ελαττώσει τις πιθανές επιπλοκές. Σκοπός της εργασίας είναι να διερευνήσει μέσα από την υπάρχουσα βιβλιογραφία κατά πόσο η αεροβική άσκηση κατά τη διάρκεια της εγκυμοσύνης είναι ασφαλής και ποιες είναι οι εναλλακτικές επιλογές για τη μέλλουσα μητέρα. Έχει αποδειχθεί ότι η άσκηση επηρεάζει θετικά τόσο το σώμα της γυναίκας όσο και την ψυχολογία της. Προλαμβάνει προβλήματα στη σπονδυλική στήλη, στο καρδιαγγειακό σύστημα, αλλά και στη διάθεσή της τόσο κατά τη διάρκεια της εγκυμοσύνης, όσο και μετά τη γέννα.
Current guidelines regarding recommended exercise in pregnancy appear consistent with reported research regarding fetal heart changes in response to maternal exercise. Fetal heart rate increases during pregnancy, but maternal exercise appears well tolerated if performed in uncomplicated pregnancies and not in the supine position. Maximal levels of exercise that are well tolerated by the fetus have not yet been well defined; however, recent literature suggests that sustained exercise during pregnancy may have beneficial effects on autonomic control of fetal heart rate and variability that may lead to long-term health benefits.
Aim:
To test the hypothesis that autonomic neural activity in pregnant women during exercise varies according to gestational age.
Methods:
This cross-sectional study involved 20 healthy women in their second (n = 13) or third (n = 7) trimester of pregnancy. Incremental cardiopulmonary exercise testing was performed with an electromagnetic cycle ergometer. Heart rate variability was analyzed by frequency analysis software.
Results:
The low-frequency to high-frequency (LF/HF) ratio, an indicator of the sympathetic nervous system, was significantly higher in third trimester than in second trimester subjects (P < 0.05) at 1, 2, and 3 min of incremental exercise testing. In contrast, the HF/total power ratio, an indicator of rapidly acting parasympathetic activity, was significantly higher in second trimester than in third trimester subjects (P < 0.05) at 2 and 3 min. In addition, a negative correlation was found between gestational age and the 'accumulation half-time' of the LH/HF ratio, the time point at which the sum of the LF/HF ratio reached 50% of that accumulated in the total 6 min of exercise testing (r = -0.49, P = 0.028).
Conclusions:
The autonomic response to exercise in pregnant women differs between the second and third trimesters. These differences should be considered when prescribing exercise to pregnant women.
Ontspanning en ademhaling zijn nauw met elkaar verbonden. Enerzijds is ontspanning niet goed mogelijk wanneer de ademhaling wordt belemmerd, anderzijds is rustig ademhalen moeilijk voor wie gespannen is. De ademhaling wordt niet voor niets de spiegel van de emoties genoemd. Met ontspanningsoefeningen kan de verhoogde spierspanning worden verlaagd tot het normale niveau van basisspanning. Dit is mogelijk door bij een goed lichaamsbewustzijn overbodige spierspanning te signaleren en deze los te laten. Iedere spier heeft zijn eigen basisspanning. Een constant aanwezige, te hoge spanning in een bepaalde spier is verspilling van energie en kan leiden tot een verhoogde basisspanning, pijnklachten of zelfs functiestoornissen. Toename van spierspanning kan veroorzaakt worden door fysieke inspanning of pijn, maar ook door psychische spanning als depressie en angst.
Trainen in de zwangerschap met gezonde, actieve vrouwen levert in principe geen risico's op voor de aanstaande moeder en haar ongeboren baby.Wel zijn er richtlijnen en criteria voor trainen in de zwangerschap, waaraan zowel de ZwangerFit-docent als de cursist zich dient te houden. Behalve deze richtlijnen zijn er ook contra-indicaties en relatieve contra-indicaties, die na de intakeprocedure al vóór de eerste actieve les ZwangerFit bekend zijn. Voor en tijdens iedere les let de ZwangerFit-docent op ‘waarschuwingssignalen’. Bij twijfelgevallen kan de docent contact opnemen met de begeleidend arts of verloskundige. Ditzelfde geldt uiteraard ook voor de pas bevallen vrouwen in de postpartumgroep.
Fitness is een verzamelnaam voor oefeningen die gedaan kunnen worden, al dan niet met gebruik van apparatuur. Meestal wordt fitness beoefend in een sportschool, fitnesscentrum of fysiotherapiepraktijk. Belangrijk is de instructie hoe te bewegen: ondeskundige fitnessoefeningen kunnen tot schade leiden. De ZwangerFit-docent die fitnesselementen toepast in de actieve ZwangerFit-lessen, is deskundig in het gebruik van de fitnessapparatuur en als algemeen fysiotherapeut ervaren in het trainen van spieren. Daarnaast is de ZwangerFit-docent gespecialiseerd in het actief begeleiden van vrouwen in hun zwangerschap of postpartumperiode, al dan niet met fitness.
Synopsis Transgenerational epigenetics, the study of non-genetic transfer of information from one generation to the next, has gained much attention in the past few decades due to the fact that, in many instances, epigenetic processes outweigh direct genetic processes in the manifestation of aberrant phenotypes across several generations. Maternal effects, or the influences of maternal environment, phenotype, and/or genotype on offsprings' phenotypes, independently of the offsprings' genotypes, are a subcategory of transgenerational epigenetics. Due to the intimate role of the mother during early development in animals, there is much interest in investigating the means by which maternal effects can shape the individual. Maternal effects are responsible for cellular organization, determination of the body axis, initiation and maturation of organ systems, and physiological performance of a wide variety of species and biological systems. The cardiovascular system is the first to become functional and can significantly influence the development of other organ systems. Thus, it is important to elucidate the role of maternal effects in cardiovascular development, and to understand its impact on adult cardiovascular health. Topics to be addressed include: (1) how and when do maternal effects change the developmental trajectory of the cardiovascular system to permanently alter the adult's cardiovascular phenotype, (2) what molecular mechanisms have been associated with maternally induced cardiovascular phenotypes, and (3) what are the evolutionary implications of maternally mediated changes in cardiovascular phenotype?. © The Author 2014. Published by Oxford University Press on behalf of the Society for Integrative and Comparative Biology. All rights reserved.
Introduction: pregnancy determines adaptive systemic and local modifications, with the main objective to promote fetal growth and development. These are physiological adaptations and occur in reaction to the presence of a fetus and his tissues, modulated by the enhanced action of several trophoblastic/placental, fetal, and maternal hormones. In spite of these physiological adaptations, pregnant women benefit from regular exercise. However, there are still controversies, both in relation to the practice of regular exercise during pregnancy and fetal risk imposed by exercises.
Objectives: to carry out a bibliographic research on the physiological alterations and physical exercise in pregnancy and fetal responses to its effects.
Methodology: a systematic review addressed physiological alterations and physical exercises in pregnancy, from the 80s to the present.
Results: there was significant increase in fetal HR (heart rate) after the protocol of exercises without fetal distress (SF). However, when the maternal HR exceeded 140 bpm, SF happened.
Conclusion: the practice of physical exercise at moderate intensity (up to 140 bpm of maternal HR) seems beneficial to the mother and fetus in non-complicated pregnancies.
Statement of problemFew studies have examined the influence of physical activity on sleep among pregnant women. To examine the potential sleep-enhancing benefits of physical activity among pregnant women and to therefore see if physical activity may serve as a non-pharmacological treatment for sleep disturbances during pregnancy, this study’s purpose was to examine the association between objectively-measured physical activity and sleep among a nationally representative sample of U.S. pregnant women.Methods
Data from the National Health and Examination Survey 2005–2006 was used for the present study. 138 pregnant women who had worn an ActiGraph 7164 accelerometer on the right hip for at least 4 days for a minimum of 10 h per day were identified. Questions on sleep were asked during the household interview.ResultsOf the 22 sleeping-related parameters assessed, physical activity was only associated with two. After controlling for depression, gestation, income and parity, for every 1-min increase in moderate-to-vigorous physical activity, pregnant women were 17% less likely to have difficulty finishing a meal because of being tired or sleepy (OR = 1.17, 95% CI: 0.98–1.38, p = 0.06).Conclusion
Our data suggests a weak relationship between objectively-measured physical activity and sleep. Additional research using a larger sample of pregnant women, as well as experimental studies, are needed to determine the extent to which physical activity may assist in improving sleeping-related parameters among pregnant women.
Objectif:
Énoncer une directive canadienne visant à informer les fournisseurs de soins obstétricaux des répercussions, pour la mère, le fœtus et le nouveau-né, des exercices de conditionnement aerobique et musculaire pendant la grossesse. RéSULTATS ATTENDUS: Effets sur la morbidité maternelle, fœtale et néonatale et mesures de la forme physique maternelle.
Preuves:
Une recherche sur MEDLINE des articles, publiés en anglais de 1966 à 2002, appartenant aux catégories suivantes : études sur le conditionnement aérobique et musculaire chez des femmes ne faisant pas jusque-là d'exercice et chez des femmes actives avant leur grossesse, ainsi que des études sur les répercussions du conditionnement aérobique et musculaire sur les issues précoces et tardives de la grossesse ou sur les issues néonatales; rapports de synthèse et méta-analyses portant sur l'exercice pendant la grossesse.
Valeurs:
Les résultats recueillis ont été revus par la Société des obstétriciens et gynécologues du Canada (Comité de la pratique clinique - obstétrique), avec la participation de la Société canadienne de physiologie de l'exercice, et ils ont été classés suivant les critères d'évaluation des preuves établis par le Groupe de travail canadien sur l'examen de santé périodique.
Recommandations:
VALIDATION: Cette directive a été approuvée par le Comité de pratique clinique - obstétrique de la SOGC, par le Comité exécutif et par le Conseil de la SOGC, ainsi que par le Conseil d'administration de la Société canadienne de physiologie de l'exercice. PARRAINé PAR: la Société des obstétriciens et gynécologues du Canada et par la Société canadienne de physiologie de l'exercice.
Pregnant mares are often removed from work during gestation. However, little is known about the effects of exercise on the pregnant mare and her foetus. In the present study, maternal and foetal heart rates were monitored by electrocardiography before and after exercise in four equine pregnancies (days 250–285). Exercise consisted of lungeing mares in 20 m circles for 5, 10 and 20 min. Following exercise, significant increases in maternal heart rate were detected (P<0.0001) but not in foetal heart rate (P = 0.4331). All mares gave birth to normal foals uneventfully. While these findings suggest that moderate exercise of the pregnant mare does not appear to be harmful to the equine foetus, data are insufficient to draw conclusions. A larger, more controlled study is necessary.
A través de la historia, las recomendaciones acerca del ejercicio durante la gestación han estado basadas más en razones sociales y culturales que en evidencias puramente científicas. Tradicionalmente, los consejos médicos alentaban a la moderación, aunque el concepto de "moderado" era algo conservador. No obstante, esta opinión no se dirigía en la misma dirección del creciente número de mujeres incluidas en programas de actividades físicas recreacionales y deportes. Actualmente, con el ejercicio físico convertido en una parte integral de la vida de muchas mujeres, la pregunta con respecto a la posibilidad de un efecto negativo del ejercicio físico en los resultados del embarazo, tiene cada vez más importancia. Por lo tanto, se hace necesaria información relativa a la interacción entre el ejercicio físico y la gestación. Nuevos conocimientos ayudarán a establecer guías trabajo actualizadas sobre cómo desarrollar un programa de actividad física durante el embarazo. En ese sentido, se hace importante destacar al embarazo como el único proceso en el cuál casi todos los sistemas corporales de la mujer se modifican en un intento de mantener el equilibrio materno y fetal. En teoría, la practica de ejercicio podría representar un cuestionamiento para el bienestar materno y fetal, especialmente si este ejercicio se realiza a altas intensidades. Desde un punto de vista biológico, el doble conflicto creado por las necesidades del ejercicio y el embarazo podría ocasionar problemas relacionados con el fluido de sangre uterina, la fuente alimento muscular utilizada, la temperatura materna y fetal, etc. En relación a esto último, en la pasada década, estudios fisiológicos acerca de la respuesta materna al ejercicio durante la gestación aseguran que mujeres sanas tienen la capacidad de acomodarse a las, a menudo conflictivas, demandas fisiológicas de ambos procesos: ejercicio y gestación. No obstante, a pesar de estos avances acerca de la fisiología del ejercicio durante la gestación, en general, existe todavía una falta de consenso en relación a los efectos del ejercicio en los resultados del embarazo. En ese sentido, los efectos de la actividad física sobre estos resultados son todavía no muy bien entendidos. Por lo tanto, el propósito de este trabajo de investigación es conocer los efectos del ejercicio aeróbico moderado sobre los resultados del embarazo. Presentamos a continuación un trabajo de tipo experimental referente a los efectos del ejercicio físico desarrollado durante el segundo y tercer trimestre de embarazo. Se trata de un estudio del tipo Casos y Controles. Entre el 1 de Mayo de 2000 y el 30 de septiembre de 2001, un total de 480 mujeres fueron entrevistadas en su primera visita prenatal obteniendo con ello datos acerca de sus características médicas, sociales, laborales, hábitos de actividad física diaria y su consentimiento para participar en este estudio. Todas las participantes de este trabajo fueron contactadas a través de las consultas de Obstetricia del Hospital Severo Ochoa de Leganés, Madrid. Un total de 72 mujeres, sin complicaciones en su embarazo (ni embarazo gemelar) fueron asignadas de forma aleatoria al grupo de Tratamiento (casos) y 70 mujeres, con los mismos criterios de inclusión, formaron parte del grupo Control. El programa de ejercicios consistió en tres clases semanales de 35 minutos durante el segundo y tercer trimestre de embarazo conducidas por un Licenciado en CC de la Actividad Física y el Deporte, siguiendo la líneas directrices del ACOG (Colegio Americano de Obstetras y Ginecólogos). El carácter moderado de la actividad se basó en el gasto calórico semanal de aproximadamente 1000 Kcal gastadas en las tres clases. El tratamiento estadístico de los datos se realizó por medio del programa SPSS, versión 10.0, propiedad de la Universidad Politécnica de Madrid. Se tuvieron en cuenta otros factores que podían ser influyentes en los resultados (variables "confundidoras") tales como edad, paridad, tabaquismo, actividad laboral, hábitos de ejercicio anterior al embarazo, etc. Nuestros resultados no muestran asociación entre practica de ejercicio físico durante el embarazo y complicaciones en el curso de la gestación ni resultados adversos de la misma. Asimismo encontramos que las gestantes del grupo Tratamiento (ejercicio) ganan menos peso y tienen bebes con menor peso de nacimiento que las del grupo Control (no ejercicio); todo ello dentro de niveles considerados como normales. En conclusión, los resultados de nuestra investigación sugieren que mujeres sanas, sin complicaciones en su embarazo, pueden practicar ejercicio aeróbico moderado durante su segundo y tercer trimestre de embarazo, sin que ello altere el normal proceso de embarazo y parto, ni ocasione alteraciones en el normal crecimiento y desarrollo fetal.
To investigate the effects of exercise on the pregnant woman and her fetus, 20 pregnant women were studied during the second and third trimesters. Twelve of the women participated in an aerobic exercise program while eight women did not perform any regular exercise and served as a control group. On the basis of submaximal exercise test results, an 18% improvement and a 4% decline in absolute aerobic capacity (liters of oxygen per minute) were observed in the exercise and control groups, respectively. Functional aerobic capacity (milliliters of oxygen per kilogram per minute) rose 8% in the exercise group and declined 10% in the control group. A small but significant rise in fetal heart rate was measured during the exercise sessions. A comparison of pregnancy outcome of the two groups showed no differences in labor duration, Apgar scores, or fetal growth.
A study was made of the effects of maternal exercise on fetal plasma concentrations of catecholamines in nine ewes with chronically catheterized singleton fetuses at 125 to 137 days' gestation. The ewes were subjected to acute treadmill exercise of 2.5 mph for 45 minutes with continuous recording of maternal and fetal blood pressures. Samples of arterial blood were obtained for measurement of catecholamines, glucose, and blood gases. Changes in blood flow in fetal organs in response to maternal exercise were assessed by injection of radioactive microspheres. The maternal plasma catecholamine responses were related to the severity of the exercise stress as indicated by the index of cardiac effort. The fetal responses did not correlate with maternal cardiac effort. A significant decrease in fetal Po2 with a moderate alkalosis occurred, accompanied by a significant elevation in circulating levels of norepinephrine. At the peak of exercise, there was an increase in fetal renal, adrenal, and placental blood flows, as compared to the control period.
Autonomic nervous control of heart rate (HR) during hypoxia was studied longitudinally using 9 chronically catheterized fetal lambs (109 day to term) and 10 newborn lambs (2--28 days old). Changes in heart rate (deltaHR) during hypoxia were age-dependent. Before 120 days of gestation deltaHR was insignificant, but between 120 days to term bradycardia occurred. The newborn response was marked tachycardia. Autonomic influences on HR were quantified using atropine and propranolol blockade. In fetal lambs, antagonistic increases in parasympathetic and sympathetic outflows were evident during hypoxia. In hypoxic lambs 120 days to term, net bradycardia reflected predominant parasympathetic cardio-deceleration; before 120 days of gestation both the parasympathetic and sympathetic outflows increased, but no net deltaHR occurred. In hypoxic newborn lambs, sympathetic and parasympathetic changes contributed synergistically to the net tachycardia. Thus the pattern of autonomic control of HR during hypoxia differs in fetal and newborn lambs. Changes in sympathetic and parasympathetic influences are antagonistic in the fetus, but synergistic in the newborn.
5-day-old neonatal offspring of exercised or non-exercised pregnant Sprague Dawley rats were used to prepare primary cultures of beating myocardial cells. The cells from the exercise group exhibited a slower beating rate for both single and aggregate cells; a larger cell size; an increased percentage of contracting cells; a greater capacity to form confluent monolayers, and a greater viability. It was concluded that exercise during the period of pregnancy produced morphological alterations in the myocardium of the progeny.
The purpose of our study was to test the hypothesis that regular recreational exercise increases the rate of growth in placental volume in the midtrimester of human pregnancy.
Serial measurements of placental volume were obtained between the fourteenth and twenty-sixth gestational week in 18 subjects who exercised regularly throughout the midtrimester and in 16 matched controls with an ultrasonographic system equipped with a fixed-base, articulated-arm, 3.5 MHz B-mode transducer.
Placental volumes were significantly greater in the women who maintained a regular exercise regimen throughout the midtrimester. At 16 weeks (mean +/- SD) volumes were 141 +/- 34 cm3 and 106 +/- 18 cm3 in the two groups. This difference increased at 20 weeks (265 +/- 67 cm3 vs 186 +/- 46 cm3) and again at 24 (410 +/- 87 cm3 vs 270 +/- 58 cm3) weeks' gestation because of a significant between-group difference in the rate of growth in placental volume over this time interval (34 +/- 8 cm3/wk vs 21 +/- cm3/wk).
We conclude that the hypothesis is correct and speculate that the change in growth rate represents an adaptive response to the intermittent stimulus of a reduction in regional blood flow.
Fetal responses to maximal maternal exercise were studied during cycle ergometry and tethered swimming in 13 untrained subjects at 25 and 35 weeks' gestation. The fetal heart rate (FHR) and uterine and umbilical artery waveforms were measured before exercise, immediately after exercise, and at 5-minute intervals during 20 minutes of recovery. The mean maternal maximal heart rate was 179 +/- 12 beats per minute and did not differ between swimming and cycling exercise trials. Six episodes of transient bradycardia occurred after a total of 45 maximal exercise trials. The mean FHR decreased slightly immediately after exercise, then increased approximately ten beats above baseline levels at 10-20 minutes after exercise (P less than .02). The changes from baseline in FHR were greater after cycling than after swimming. Changes observed in the systolic-diastolic ratio (S/D) of the umbilical artery could be accounted for by the FHR variations. The S/D of the uterine artery was significantly higher after cycling than after swimming (P = .05). We conclude that maximal maternal exercise during pregnancy causes transient fetal bradycardia in approximately 15% of cases, in cycling more often than in swimming.
Seven women at 25 weeks' gestation exercised on land and in the water at 70% maximum oxygen capacity (VO2max) on a bicycle ergometer. Women had significantly lower heart rates and lower systolic blood pressures during immersion exercise. Women had a mean diuresis of 207 ml (6.5 ml/min) during water exercise compared with 98 ml. (2.4 ml/min) during land exercise. Fetal heart rates showed a tendency toward being higher after land exercise compared with water exercise. Six of seven fetuses displayed tachycardia after land exercise compared to one of seven after water exercise. Exercise on land and during immersion at 70% VO2max was well tolerated. However, exercise during immersion offers several physiologic advantages during pregnancy.
The purpose of this study was to investigate the possibility that motion artifact may override the recording of fetal heart rate (FHR) with Doppler ultrasound fetal monitors during maternal exercise on cycle ergometers and treadmills, and to test the efficacy of two-dimensional ultrasound directed M-mode echocardiographs for determining FHR during maternal treadmill exercise. Four pregnant women (26 to 30 yr, means = 28, gestational age = 28 to 34 wk) pedaled a cycle ergometer at 25 to 50 W, while a second group (N = 4) (24 to 36 yr, means = 29, gestational age = 30 to 37 wk) walked on a treadmill at either 1.5 or 2.0 mph. Fetal monitor recordings (Hewlett-Packard 8040A) were consistent with pedal rate in the range of 50 to 70 rpm and with stepping rate in the range of 70 to 76 steps per min at 1.5 mph and 100 to 106 steps per min at 2.0 mph on the treadmill. Actual mean FHRs (audible signal from fetal monitor) were in the normal range [150.5 +/- 10.25 bpm (cycle ergometer) and 148.8 +/- 2.3 bpm (treadmill)]. In a separate session, the cycle ergometer group walked on a treadmill at a maternal heart rate of 140 bpm while FHR was determined by two-dimensional ultrasound directed M-mode echocardiographs. Off-line analysis of fetal cardiac cycle time (clinical graphics analyzer) allowed accurate FHR measurements which were not confounded by motion artifact. Mean FHR during maternal treadmill exercise (158.0 +/- 12.0 bpm) was not different (P greater than 0.05) when compared to pre-exercise standing (140 +/- 3.6) and also during the post-exercise period (sitting) (151 +/- 6.5) compared to the sitting pre-exercise measurements (147 +/- 8.2).(ABSTRACT TRUNCATED AT 250 WORDS)
The fetal heart rate responses to mild, moderate, and strenuous maternal exercise were studied in 45 healthy subjects. In the majority of cases, the fetal heart rate increased during and after maternal exercise. Fetal bradycardia was recorded in five fetuses; this appears to be a sporadic event. There was no correlation between the individual fetal heart responses, gestational age, exercise intensity, and maternal circulating catecholamines.
Six healthy active women in the third trimester of pregnancy participated in a graded exercise protocol to levels of exertion perceived to be equivalent to that of their usual exercise regimen. Fetal heart rate response (FHR) was documented by ultrasound transducer and confirmed (n = 1) by ultrasonic visualization. Resting maternal O2 consumption was 277 +/- 50 (SD) ml/min and rose to 1,132 +/- 202 ml/min at a mean final exercise intensity of 79 +/- 9 W after 12.8 +/- 1.7 min on a cycle ergometer. There was no significant change in maternal serum insulin, growth hormone, glucose, or pH values. Maternal leukocyte count, hemoglobin, and venous lactate levels rose significantly during the exercise (P less than 0.05). FHR prior to exercise was 142 +/- 4 beats/min and decreased to 84 +/- 34 beats/min during exercise. The decrease in FHR was documented within 1 min of initiating exercise in all cases. During exercise, fetal movements were not accompanied by FHR accelerations. Within 1 min following the cessation of exercise, FHR rose to 143 +/- 8 beats/min and fetal movements were accompanied by FHR accelerations. Since the recovery of FHR occurred immediately after cessation of maternal exercise, this level of maternal exercise does not appear to be harmful to the fetus.
Heart rate and stroke volume were measured serially in subjects at rest in the sitting position and at the onset and end of a 6-minute period of upright bicycle exercise. Twenty-three subjects with normal pregnancy were studied in late gestation and again post partum. Rest and exercise cardiac outputs in late gestation were not different from those in the postpartum period. Heart rate was higher at rest and stroke volume lower during exercise in late gestation than post partum. At the end of exercise, stroke volume fell dramatically in late gestation but not post partum. Ten women prospectively identified as physically fit had responses that were not different from those of the nonfit cohort in late gestation. Post partum, the physically fit women had exercise responses typical of trained persons and different from those of the nonfit cohort. In late gestation, rest and exercise hemodynamics in subjects in the sitting position appeared to be dominated by factors influencing venous return, independent of physical fitness.
Fetal heart rate was recorded at 20 and 32 weeks' gestation before and after 20 minutes of treadmill exercise. The intensity of the exercise was matched to each woman's current training level. On every occasion the fetal heart rate rose significantly after exercise.
The nonstress test is of recognized value for the antepartum assessment of fetal well-being. Less well defined, however, is the relationship between baseline fetal heart rate, reactivity, and the gestational age of the fetus. A prospective analysis of the nonstress test in a preterm, low-risk population was begun. Weekly tests were begun as early as 23 weeks and continued to term. A test was considered reactive if there were two or more fetal heart rate accelerations within a 20-minute period. A total of 128 nonstress tests were performed on 25 low-risk patients. Of these tests, 84 (64%) were considered reactive. With advancing gestational age, a progressive increase in the incidence of reactive tests was observed. However, no significant difference in baseline fetal heart rate could be identified between term and preterm fetuses. In addition, the frequency and amount of accelerations and decelerations were determined. Decelerations were not noted more frequently in the preterm population. Conversely, accelerations occurred more frequently with advancing gestational age. The pregnancy outcome was excellent for all study patients. It is concluded, therefore, that with advancing gestational age more reactive nonstress tests are seen. Baseline fetal heart rate and the frequency of decelerations appear to be unaffected by advancing gestational age. Finally, although the numbers are small, the nonstress test appears to be a suitable technique for assessing fetal well-being in the preterm fetus.
The fetal electroencephalogram was recorded in a chronic fetal sheep preparation. Two characteristic patterns of activity were seen, one of slow-wave high voltage and a second with a rapid frequency and low voltage. The second pattern was associated with other phenomena characteristic of rapid eye movement sleep.
Rapid transfer of norepinephrine and isoproterenol from the maternal to the fetal side of the human placenta has been demonstrated in vitro. There was no evidence of stereospecificity of the norepinephrine transfer mechanism. Both monoamine oxidase and catechol O-methyltransferase were involved in the metabolism of a proportion of the norepinephrine during its transplacental passage, corresponding metabolites being identified in the fetal perfusate. Some isoproterenol underwent O-methylation. The presence of catechol O-methyltransferase activity was confirmed directly in placental homogenate. In vivo evidence of placental transfer of norepinephrine in the guinea pig was also obtained. The clinical implications of these findings are discussed.
A membrane covered tissue Po2 electrode is described which can be applied to the fetal scalp early in labour to provide a continuous measurement of fetal tissue Po2. The use of a membrane cover has reduced the oxygen consumption of the electrode and its sensitivity to diffusion conditions in the region of measurement so that it may be calibrated in absolute terms. When the oxygen concentration breathed by the mother was reduced from 100 to 21 per cent or from 21 to 15 per cent fetal tissue Po2 declined more slowly than the maternal tissue Po2. Changes in fetal tissue Po2 associated with various patterns of transitory fetal heart rate change are also presented.
Fetal bradycardia that occurred during maternal exercise (a symptom-limited VO2 max treadmill test) in the fetuses of three healthy pregnant women is described. The mechanism of this bradycardia is believed to be mediated by catecholamines. The fetal bradycardia seems to be transitory and appears to be compensated for by an increase in fetal heart rate after the cessation of exercise.
An in vitro system for the dual perfusion of an isolated lobe of human placenta was used to study transfer and metabolism of 3H-labeled norepinephrine at two different concentrations. At 39 mumol/L, the transfer of total radioactivity from the maternal to the fetal side was 11.60% +/- 0.60% and significantly higher (p less than 0.05) than that in the opposite direction (6.50% +/- 0.37%). In both directions almost 50% of tritium was transferred as norepinephrine while the rest was metabolized and appeared on the other side as normetanephrine, dihydroxymandelic acid, and vanillylmandelic acid. When a reduced concentration (870 nmol/L) was infused into either the maternal or the fetal compartment, transfer and metabolism were similar to those determined before. Analysis of the tissue showed 50% of total radioactivity as normetanephrine, dihydroxymandelic acid, and vanillylmandelic acid and 17% as conjugates. Inclusion of the monoamine oxidase inhibitor clorgyline in the perfusate significantly reduced fetal-to-maternal transfer but not transfer in the reverse direction. In addition, inhibition of placental monoamine oxidase resulted in a considerable reduction in dihydroxymandelic acid and vanillylmandelic acid while the normetanephrine fraction increased. Norepinephrine significantly increased glucose utilization and lactate production. A possible physiologic role of norepinephrine transferred from the fetal into the maternal circulation during labor is discussed.
A study was made of the effects of maternal exercise on fetal plasma concentrations of catecholamines in nine ewes with chronically catheterized singleton fetuses at 125 to 137 days' gestation. The ewes were subjected to acute treadmill exercise of 2.5 mph for 45 minutes with continuous recording of maternal and fetal blood pressures. Samples of arterial blood were obtained for measurement of catecholamines, glucose, and blood gases. Changes in blood flow in fetal organs in response to maternal exercise were assessed by injection of radioactive microspheres. The maternal plasma catecholamine responses were related to the severity of the exercise stress as indicated by the index of cardiac effort. The fetal responses did not correlate with maternal cardiac effort. A significant decrease in fetal Po2 with a moderate alkalosis occurred, accompanied by a significant elevation in circulating levels of norepinephrine. At the peak of exercise, there was an increase in fetal renal, adrenal, and placental blood flows, as compared to the control period.
To investigate the effects of exercise on the pregnant woman and her fetus, 20 pregnant women were studied during the second and third trimesters. Twelve of the women participated in an aerobic exercise program while eight women did not perform any regular exercise and served as a control group. On the basis of submaximal exercise test results, an 18% improvement and a 4% decline in absolute aerobic capacity (liters of oxygen per minute) were observed in the exercise and control groups, respectively. Functional aerobic capacity (milliliters of oxygen per kilogram per minute) rose 8% in the exercise group and declined 10% in the control group. A small but significant rise in fetal heart rate was measured during the exercise sessions. A comparison of pregnancy outcome of the two groups showed no differences in labor duration, Apgar scores, or fetal growth.
Maternal-fetal effects of cycle ergometer conditioning (heart rate of 145 beats/min at 25 min/day for 3 days/wk) were studied during the second and third pregnancy trimesters. Subjects were 22 previously sedentary women and 16 nonexercising pregnant control women. Fetal heart rate (FHR) characteristics were studied before, during, and after 15 min of upright cycling at a maternal heart rate target of 145 beats/min at the end of both the second and third trimesters. Despite higher cycling power outputs in the exercised group, mean FHR responses were similar in both groups and conformed to 1) gradual increase in FHR baseline during exercise, 2) normal variability, and 3) normal reactivity. Fetal bradycardia was observed during (n = 1) and after (n = 2) exercise in three isolated tests. The timing of these events suggested that the likelihood of significant fetal hypoxia is highest in the immediate postexercise period. These results also support the hypothesis that physically conditioned women can perform at higher exercise power outputs than sedentary women without inducing fetal hypoxic stress. Further study is recommended to examine possible fetal and placental adaptations to maternal aerobic conditioning.
Effects of cycle ergometer conditioning (heart rate 143 +/- 2 beats/min, 25 min/session, 3 sessions/wk) during the second and third trimesters of pregnancy were studied in 18 healthy previously sedentary women. A nonexercising control group (n = 9) was also studied. Graded exercise tests were conducted for both groups at approximately 17, 27, and 37 wk of gestation and at 20 wk postpartum. Both groups exhibited augmented ventilatory responses to exercise throughout pregnancy. Significant aerobic conditioning effects observed in the exercised group between entry and third trimester of pregnancy testing included a 17% increase in oxygen pulse at peak exercise, reduction in the respiratory exchange ratio during standard submaximal exercise, and an increase in work rate at the onset of blood lactate accumulation. Onset of blood lactate accumulation did not change significantly in the control group. Respiratory exchange ratio at peak exercise was higher in postpartum tests compared with those conducted in late gestation in both groups. Peak postexercise lactate levels were also significantly lower in second and third trimesters of pregnancy testing compared with postpartum in the control group. This effect appeared to be prevented by physical conditioning in the exercised group. The study results support the hypothesis that moderate aerobic conditioning increases maximal aerobic power and the capacity for sustained submaximal exercise. Chronic exercise also appeared to help to preserve anaerobic working capacity in late gestation.
In the past decade, physical health fitness has become increasingly more important in the lives of women of child-bearing age. Many have made regular, and sometimes vigorous commitments to exercise programs. In 1985, the American College of Obstetricians and Gynecologists (ACOG) developed a set of guidelines for women who plan to exercise during pregnancy. Recommendations were based on available, but somewhat limited, scientific data and common sense. Since that time, researchers have learned a significant amount of new information about how a pregnant woman and her fetus respond to aerobic activity. The objective of this communication is to review recent investigations in this area. Specific topics include a) maternal responses to exercise, b) fetal responses to maternal exercise, c) animal research models, and d) pregnancy and physical conditioning. Our objectives are to present information that will a) stimulate new and innovative research designs for exercise and pregnancy studies, and b) add significantly to our knowledge and ability to develop safe and effective exercise programs for women who wish to remain physically active throughout a normal-term pregnancy.
We aimed to test the hypotheses that fetal heart rate increases during and after sustained exercise and that the magnitude of the increases is related to gestational age and the duration, intensity, and type of exercise.
Maternal oxygen uptake and fetal heart rate were monitored in 120 regularly exercising women in association with routine 20-minute workouts between 16 and 39 weeks' gestation.
In 97% of the studies fetal heart rate increased during and after exercise. This was significant at all gestational ages and with all forms of exercise with an overall increase of 15 +/- 11 beats.min-1 at 60% +/- 12% of maximal aerobic capacity (mean +/- SD). The magnitude increased with gestational age (10 +/- 8 to 20 +/- 11 beats.min-1), exercise intensity (8 +/- 7 to 21 +/- 13 beats.min-1), and exercise duration (8 +/- 4 to 16 +/- 7 beats.min-1).
We concluded that the hypothesis is correct and speculate that these changes represent a maturing fetal response to a reduction in Po2.
The endocrine effects of pregnancy cause striking changes in maternal metabolism, cardiovascular regulation, acid-base balance, and thermoregulation at rest and during standard submaximal exercise. The apparent purpose of these changes is to accommodate fetal needs in addition to those of the exercising woman. A significant body of evidence supports the hypothesis that healthy women can perform acute exercise of moderate intensity and duration without jeopardizing fetal well-being. Compiled studies also suggest that maximal oxygen uptake (VO2max, L.min-1) and the work rate at the onset of blood lactate accumulation (OBLA) are not significantly altered during the course of a normal pregnancy. However, some evidence suggests that maximal anaerobic power may be reduced. More information is needed on maternal cardiorespiratory function, carbohydrate metabolism, and acid-base balance at exercise intensities above OBLA and on fetal adaptability to strenuous maternal exercise. Recent studies support the view that moderate fitness conditioning can augment maternal metabolic and cardiopulmonary capacities without altering fetal development or pregnancy outcome. Implications of recent scientific studies for the design of aerobic exercise programs for pregnant women are discussed.
To study the ventilatory effects of closely monitored cycle ergometer conditioning (HR target, 145-150 beats x min(-1); 25 min/session; three sessions per week) during the second and third pregnancy trimesters (TMs) in healthy human pregnancy.
Subjects were 27 previously sedentary pregnant women (exercised group, EG). A sedentary control group (CG, N = 20) was also studied. Subjects were tested at rest and during upright cycle ergometry at three steady-state power outputs (approximately 20, 45, and 65 W) at the start of the second TM (ENTRY), at the end of the second and third TMs (post-training), and 3 months postpartum (PP, nonpregnant control).
Significant reductions in exercise HR were observed in the EG at each exercise level, confirming achievement of an aerobic conditioning effect. In both groups the ventilatory equivalent for oxygen (VE/O2) was significantly higher at all work rates during pregnancy compared with that during PP. This effect was caused by significantly higher exercise tidal volumes (VT) at each work rate in both groups during pregnancy versus PP. Respiratory sensitivity as reflected by the ventilatory equivalent for carbon dioxide (E/VECO2) and calculated arterial carbon dioxide tension (PaCO2) was significantly increased at all three work rates in late gestation versus PP and increased slightly with advancing gestational age in both groups. The main effects of physical conditioning were attenuation of increases in VE/VO2 observed at all exercise levels between the end of TM2 and TM3 and reductions in respiratory perception of effort (RPEr) between ENTRY and the end of TM3. Attenuation of increases in VE/VO2 during TM3 in the EG was attributed to the combined effects of enhanced fat versus carbohydrate utilization (resulting in reduced CO2 output and drive to ventilate) and attenuation of pregnancy-induced increases in dead space ventilation in late gestation.
The study results support the hypothesis that physical conditioning reduces both ventilatory demand and respiratory perception of effort in late gestation.