Fetal wellbeing may be compromised during strenuous exercise among pregnant elite athletes
ABSTRACT To study fetal wellbeing and uteroplacental blood flow during strenuous treadmill running in the second trimester.
Six pregnant Olympic-level athletes in endurance events aged 28-37 years and training 15-22 h per week before the pregnancy were tested once at 23-29 weeks of pregnancy. The women ran three to five submaximal workloads on a treadmill with approximately 60-90% of maximal oxygen consumption. The maternal-fetal circulation was assessed with Doppler ultrasound of the uterine and umbilical arteries before, during and after exercise.
Mean uterine artery volume blood flow was reduced to 60-80% after warming up and stayed at 40-75% of the initial value during exercise. Fetal heart rate (FHR) was within the normal range (110-160 bpm) as long as the woman exercised below 90% of maximal maternal heart rate (MHR). Fetal bradycardia and high umbilical artery pulsatility index (PI) occurred when the woman exercised more than 90% of maximal MHR and the mean uterine artery volume blood flow was less than 50% of the initial value. FHR and umbilical artery PI normalised quickly after stopping the exercise.
Exercise at intensity above 90% of maximal MHR in pregnant elite athletes may compromise fetal wellbeing.
Article: Sport und Schwangerschaft[Show abstract] [Hide abstract]
ABSTRACT: Der Nutzen von Bewegung und körperlicher Aktivität in der Schwangerschaft ist mittlerweile unumstritten. Regelmäßige sportliche Betätigung unterstützt nicht nur die gesunde Lebensführung in der Schwangerschaft und das Wohlbefinden der werdenden Mutter, sondern kann wohl auch das Risiko für Gestationsdiabetes oder Präeklampsie verringern bzw. sich positiv auf den Verlauf dieser Erkrankungen auswirken. Der Geburtsverlauf scheint ebenso von körperlicher Aktivität während der Schwangerschaft zu profitieren wie die Gewichtsentwicklung der Mutter. Die fetale Entwicklung und Sicherheit erleben durch die körperliche Belastung der Schwangeren zumeist keine Einschränkung, sofern bei der Wahl der Sportart das individuelle Risikoprofil und das Gefährdungspotenzial der Sportart berücksichtigt werden. Dabei spielen nicht nur die Sportart, sondern auch Intensität und Dauer der sportlichen Betätigung eine bedeutende Rolle. Anhand der neuesten Ergebnisse und bestehenden Leitlinien soll ein praktischer Leitfaden zur Beratung der schwangeren Patientin gezeichnet werden.Der Gynäkologe 05/2013; 46(5). DOI:10.1007/s00129-012-3101-y
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ABSTRACT: Objectives: To investigate how cardiac function, remodeling and gene expression are affected in pregnancy in response to cardiovascular stress, to detect possible adverse effects on the fetus, and to evaluate if coronary endothelial function is influenced by pregnancy and increased cardiac afterload. Methods: Pregnant and non-pregnant rats were subjected to chronic AngII-infusion, transverse aortic constriction (TAC) or high-intensity interval training (HIIT) in three separate studies. Echocardiography was used to evaluate maternal heart function. Doppler signals from the left coronary artery was used to asses coronary flow reserve (CFR) using 3.5% inhaled isoflurane as a vasodilating agent. Blood pressure and left ventricle (LV) pressure and volume were measured invasively using a conductance catheter placed in the LV. Histological sections of the maternal LV were used to determine collagen content, vessel density and myocyte size. RT-PCR was used to quantify the gene expression in maternal myocardium and fetuses. Level of oxidative stress was measured in fetal tissue in the HIIT-study. Results: Chronic AngII infusion resulted in increased myocardial collagen content, and pregnancy reduced this effect. A decrease in LV vessel density following AngII infusion was less severe in pregnant rats. Calculated stroke work in pregnant TAC rats was double compared to pregnant shams, whereas it was not significantly increased in non-pregnant TAC rats compared to non-pregnant shams. The ratio of β-MHC to α-MHC expression was higher in pregnant compared to non-pregnant TAC. HIIT did not alter maternal cardiac structure or function, fetal growth or level of oxidative stress in the placenta or fetuses. There were no differences in CFR between rats with increased afterload (AngII or TAC) and controls. CFR was lower in pregnant compared to non-pregnant rats. Main conclusions: Pregnancy was protective against fibrosis and preserved angiogenesis in AngII infused rats. Increased afterload following TAC was less tolerated in pregnancy. CFR is reduced in late pregnancy. HIIT is feasible and well tolerated by pregnant rats and did not induce significant changes in the fetus.09/2014, Degree: PhD, Supervisor: Ganesh Acharya
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ABSTRACT: Abstract Purpose . The aim of the present study was to examine the influence of a program of moderate physical exercise throughout pregnancy on maternal and fetal parameters. Design . The study design was a randomized controlled trial. Setting . The study took place at the Hospital of Fuenlabrada in Madrid, Spain. Sample . Analyzed were 200 pregnant women (31.54 ± 3.86 years), all of whom had uncomplicated and singleton gestation. Of these subjects, 107 were allocated to the exercise group (EG) and 93 to the control group (CG). Intervention . Women from EG participated in a physical conditioning program throughout pregnancy, which included a total of 55- to 60-minute weekly sessions, 3 days per week. Measures . Pregnancy outcomes. Maternal: gestational age, weight gain, type of delivery, blood pressure during pregnancy, gestational diabetes (n/%). Fetal: birth weight, birth size, head circumference, Apgar score, pH of umbilical cord. Analysis . Student's unpaired t-test and χ(2) test were used; p values of ≤ .05 indicated statistical significance. Cohen's d was used to determine the effect size. Results . There were significantly more pregnant women in the CG who gained excessive weight during their pregnancies than in the EG group (CG: N = 31, 35.6% versus N = 22, 21.2%; χ(2) = 4.95; p =.02). The effect size was small (Phi value =.16). Other pregnancy outcome showed no differences between groups. Conclusion . A regular and moderate physical exercise program throughout pregnancy is not a risk to maternal and fetal well-being, and it helps to control excessive weight gain.American journal of health promotion: AJHP 11/2013; 29(1). DOI:10.4278/ajhp.130131-QUAN-56 · 2.37 Impact Factor