Article

Comparing expectant management and spontaneous labor approaches in studying the effect of labor induction on cesarean delivery

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Abstract

Purpose: Evidence of the impact of labor induction on cesarean delivery (CD) remains inconclusive because of differing methodological approaches. A spontaneous labor comparison group describes patterns retrospectively, whereas an expectant management comparison group prospectively evaluates a decision to induce. We examined the influence of comparison group on the association between labor induction and CD. Methods: We studied 166,559 mother-newborn dyads from 14 National Perinatal Information Center member hospitals, 2007-2012. We included singleton births 34-42 completed weeks' gestation and excluded women with contraindications to vaginal delivery. We calculated risk ratios (RR) adjusted for hypertensive and diabetic disorders, intrauterine growth restriction, parity, and maternal age. Results: When comparing induction to spontaneous labor, induction had significantly lower risk for CD at weeks 34-35 (adjusted RR [95% confidence interval (CI)]: 0.6 [0.5, 0.7] for week 34 and 0.7 [0.6, 0.8] for week 35) and higher risk at weeks 37-41 (adjusted RRs [95% CIs]: 1.8 [1.6, 2.1], 2.1 [1.9, 2.2], 1.8 [1.7, 1.9], 1.9 [1.8, 2.0], and 1.6 [1.5, 1.7], respectively). When comparing induction to expectant management, adjusted RRs [95% CIs] were significantly below 1.0 for week 34 (0.8 [0.7, 0.9]), week 36 (0.9 [0.8, 0.9]), and week 37 (0.9 [0.8, 0.9]), and were only elevated at week 40 (1.4 [1.3, 1.4]) and week 41 (1.4 [1.3, 1.5]). Conclusions: Using two different methodological approaches with the same sample, we confirm that comparing labor induction to spontaneous onset of labor, instead of expectant management of pregnancy, does not fully inform clinical practice and may lead to an exaggerated estimate of the risk of CD.

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... [2][3][4] Unfortunately, spontaneous labor cannot be conjured; thus, using it as a benchmark to assess labor induction outcomes is inappropriate. When, belatedly, expectant management was instead used as the analytically and clinically appropriate comparator, 5 several large observational cohorts demonstrated a lower frequency of cesarean delivery in association with induction of labor, as well as fewer cases of neonatal depression, meconium aspiration, neonatal intensive care unit admission, and perinatal death. [6][7][8][9] The recent publication of A Randomized Trial of Induction Versus Expectant Management (ARRIVE) pushes to the fore the question of whether obstetric care providers should recommend labor induction to all women who have achieved 39 weeks of gestation and are candidates for vaginal birth. ...
Article
It has long been observed that neonates born between 39 and 40 gestational weeks have the best perinatal outcomes. What has not been known, until recently, is whether these ideal perinatal outcomes would be achieved in neonates whose delivery was brought on intentionally in this window by labor induction. Recent randomized trials and large observational cohorts have answered this question: labor induction, as compared with expectant management, lowers the rate of cesarean delivery (without increasing other adverse maternal outcomes) and improves perinatal outcomes. For those women still pregnant, delivery at 39 weeks of gestation would simultaneously lower the number of cesarean deliveries and reduce the number of stillbirths and neonatal deaths in the United States.
... We considered subsets of cesarean pathways: prelabor cesarean, cesarean among women who experienced spontaneous labor, and cesarean among women who underwent labor induction. We applied a previously developed algorithm to identify spontaneous labor and prelabor cesarean deliveries [30,31]. Spontaneous labor was identified if (1) the birth certificate or delivery record did not contain codes indicative of labor induction or cesarean delivery or (2) the delivery record indicated cesarean birth but also included ICD codes indicative of active (but not induced) labor (Supplementary Material, Table S1). ...
Article
Purpose: We aimed to quantify the extent to which overweight and obesity explain cesarean delivery risk among women of different racial and ethnic backgrounds. Methods: Using administrative records for 216,481 singleton, nulliparous births in New York City from 2008 to 2013, we calculated risk ratios, risk differences, and population attributable fractions for associations between body mass index (BMI) and cesarean, stratified by race and ethnicity. Results: The population attributable fraction (95% confidence interval) for BMI was 6.8% (6.2%-7.3%) among Asian, 10.9% (10.4%-11.4%) among White, 14.6% (13.7%-15.5%) among Hispanic, and 17.4% (16.2%-18.6%) among Black women. Although overweight and obesity were most prevalent among Black and Hispanic women, the risk gradient was strongest among Whites (adjusted risk ratio [95% CI] from 1.37 [1.33-1.41] for overweight to 2.23 [2.07-2.39] for class III obesity). Additional adjustment for gestational complications partially attenuated associations, and accounting for delivery hospital eliminated the stronger gradient among White women. Conclusions: Prepregnancy overweight and obesity contribute proportionally more to cesarean risk among Black and Hispanic women because of higher prevalence compared to White or Asian women. Although preconception weight management is important to decrease cesarean risk, results encourage attention to clinical approaches in low-risk pregnancies to mitigate racial and ethnic perinatal disparities.
... Recent published data of expectant management versus induction of labor shows that there is, a significantly elevated risk for caesarean section (CS) in full time induced pregnancies, even after controlling for suspected confounders. [1][2][3][4] Misoprostol is a prostaglandin E1 analogue, developed for the treatment and prevention of gastric ulcers. Its proven efficacy of uterine contractility and cervical ripening has led to a drug currently being used for termination of unwanted pregnancy, management of incomplete and spontaneous abortions, induction of labor, augmentation of labor, and treatment of postpartum hemorrhage (PPH). ...
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Article
Background: Induction of labor is one of the great challenges for obstetric care provider. Misoprostol is used for induction of labor by various routes with the advantages in being cheap and stable at room temperature and widely available even in resource-poor settings.Methods: A randomized controlled study was conducted in the obstetrics and gynecology department of Govt. Medical College and associated Maharani Hospital, Bastar, Chhattisgarh, India over a period of 1.75 years from September 2014 to May 2016. Study has comprised of 200 pregnant women admitted in the department for induction of labor fulfilling the inclusion and exclusion criteria. Data was collected and analyzed by SPSS 16.0. z-test and chi-square test to compare the safety and efficacy of both the routes of misoprostol use for IOL.Results: There were insignificant differences in number of doses required for induction with satisfactory maternal and neonatal outcome but shorter (12 hours) induction delivery interval with sublingual Misoprostol induction. Most of the cases of both the groups were delivered by vaginal route (86% and 62%) within 12 hours of induction(58% and 42%) yet significant (p value < 0.001) number of cases had undergone caesarean in group of vaginal misoprostol administration (29%) with major indications of meconium stained liquor (3% and 12%) and non assuring fetal heart rate (1% and 10%).Conclusions: Although both the routes of induction by Misoprostol are well tolerated by the women with satisfactory neonatal outcome, sublingual Misoprostol has an added advantage of quicker delivery, less caesarean and ease of administration indicates better safety and effectiveness.
... Hence, some authors suggest that IOL outcomes are examined against expectant women who were managed within the same gestational week and not with women who had spontaneous labor as in our study. 28,29 Recently, the ARRIVE trial compared the elective IOL at 39 weeks to expectant management of labor among healthy low-risk nulliparous women. It is worth noting that although the study suggested that IOL at 39th week of pregnancy resulted in fewer cesarean rates and no significant difference in perinatal mortality and severe perinatal morbidity, only 27% (6106 out of 22,533) of women agreed to participate. ...
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Article
Objective: To explore rates and review practices regarding induction of labor (IOL) among singleton pregnancies in Palestine. Design: A prospective population-based cohort study. Setting: Six secondary and tertiary governmental hospitals located in the two regions of Palestine: West Bank and Gaza. Participants: Singleton pregnancies who had IOL in participating units during the study period were included (n=8290). Women having multiple gestations (1004), planned cesarean births (703), those admitted with cervical dilation >6cm (11228), and pregnancies with no record of cervical dilation and/or gestational age on admission (219) were excluded. Primary outcome measure: Rates of IOL in participating units and regions. Results: There were a total of 33,402 singleton births during the study period with an IOL rate of 24.8%. Rates of IOL significantly varied between units, ranging from 12.9% to 45.6% (P-value <0.05). The majority of women with no previous uterine scar were induced at gestational ages ≤40 weeks where 43.8% were induced at 39-40 gestational weeks (29.9% multiparous; 13.9% nulliparous) and 17.7% were induced between 37 and 38 gestational weeks (11.9% multiparous; 5.8% nulliparous). Conclusion: Significant variations in IOL practices between Palestinian hospitals and regions suggest overuse of IOL among singleton pregnancies in some units with the majority of these being performed before 40 weeks' gestation. These findings indicate a gap between implementation of best evidence and current clinical practice.
... Previous literature, mainly from large retrospective studies, linked low bishop score with higher rates of CD [12,13]. However, recent studies, that evaluated prospectively the chances for vaginal delivery following induction of labor at term for various indications, demonstrate similar and even lower rates of CD with induction, even with low bishop score and need for cervical ripening [14,15]. Moreover, for women with rupture of membrane at term, the TERMPROM study has long proved the efficacy of induction by either oxytocin infusion or PGE2 preparations regardless of the bishop score [16]. ...
Article
Objective: To determine predictors for cesarean delivery (CD) in pregnancies complicated by preterm premature rupture of membranes (PPROM) with an intention for vaginal delivery. Materials and methods: A retrospective cohort analysis of all singleton, preterm deliveries (24 + 0 to 36 + 6 weeks) following PPROM (2007-2014). Exclusion criteria included: cases intended for CD prior to delivery; short interval from PPROM to delivery (< 24 hours); cervical dilatation upon admission ≥ 4 cm; and major fetal anatomical/chromosomal abnormalities. Potential CD predictors were evaluated by univariate followed by multivariate regression analysis. Results: Overall, 465 deliveries met inclusion criteria. Of them, 53 (11.4%) ended with CD. Women in the CD group delivered at an earlier gestational age (34 versus 35 weeks) with lower birth weights (2115 versus 2386 grams), p < 0.05 for both. On univariate analysis, smaller cervical dilatation upon admission and prior to delivery, longer PPROM to delivery interval and delivery indication were the only significant determinants associated CD (p < 0.001 for all). On multivariable regression analysis, only larger cervical dilatation prior to delivery remained an independent factor for lower rates of CD (aOR 0.15, 95% CI 0.08–0.28, p < 0.001). Conclusion: Small cervical dilatation prior to delivery is an independent risk factor for CD in pregnancies complicated by PPROM.
... 16 It appears that the risk of ultimately being delivered by cesarean section for a pregnant woman having pregestational diabetes mellitus, hypertension, pregnancy-induced hypertension, intrauterine growth restriction, oligohydramnios or polyhydramnios, placenta previa, or for a maternal age >40 when presenting to L&D is different for a woman without such disease/condition at presentation. While these conditions may indicate the medical need for early intervention and/or induction of labor, it is important to distinguish the possibly increased risk of operative delivery that can result from induction of labor, [17][18][19] if this is simply the proper management of the respective condition. The consensus of obstetric providers suggests that intervention for the listed morbidities results in better perinatal outcome than expectant management, as is also indicated in the medical literature. ...
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Article
OBJECTIVE: To compare the likelihood of a cesarean delivery of pregnancies identified as nulliparous, term, singleton, and vertex-presenting (NTSV) and which can be deemed as low risk, with those NTSV pregnancies which can be considered as high risk according to some standards. STUDY DESIGN: Data from a single institution were used to retrospectively examine the appropriate perinatal qualifiers in order to compare the ultimate delivery type that the pregnant patient underwent, and to compare results between the low-risk and high-risk patient groups. RESULTS: Within a 7-year span of time, of the 6,146 patients who were identified as having NTSV pregnancies, there were 4,184 patients who were considered at low risk and 1,962 that were deemed at high risk of cesarean delivery, by virtue of the recognized diagnoses that were made (pregestational diabetes, gestational diabetes, chronic hypertension, pregnancy-induced hypertension, intrauterine growth restriction, oligohydram-nios or polyhydramnios, maternal age >40, or placenta previa). CONCLUSION: A statistically significant difference was found between the low-risk and high-risk NTSV patients in terms of the cesarean delivery rate for those patients. This calls into question whether the NTSV metric should represent low-risk deliveries.
... High risks of both maternal as well as fetal complications are related to induction of labor. Recent published data of expectant management versus induction of labor shows that there is a significantly elevated risk for Cesarean Section (CS) in full time induced pregnancies, even after controlling for suspected confounders [8][9][10][11]. ...
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Article
Introduction One great challenge in obstetric care is labor inductions. Misoprostol has advantages in being cheap and stable at room temperature and available in resource-poor settings. Material and Methods Retrospective cohort study of 4002 singleton pregnancies with a gestational age ≥34 w at Sodersjukhuset, Stockholm, during 2009-2010 and 2012-2013. Previously used methods of labor induction were compared with misoprostol given as a solution to drink, every second hour. Main outcome is as follows: Cesarean Section (CS) rate, acid-base status in cord blood, Apgar score < 7,5′, active time of labor, and blood loss > 1500 ml (PPH). Results The proportion of CS decreased from 26% to 17% when orally given solution of misoprostol was introduced at the clinic (p < 0.001). No significant difference in the frequency of low Apgar score (p = 0.3), low aPh in cord blood (p = 0.1), or PPH (p = 0.4) between the different methods of induction was studied. After adjustment for different risk factor for CS the only method of induction which was associated with CS was dinoproston⁎⁎ (Propess®) (aor = 2.9 (1.6–5.2)). Conclusion Induction of labor with misoprostol, given as an oral solution to drink every second hour, gives a low rate of CS, without affecting maternal or fetal outcome.
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an exciting and timely report concerning induction of labor (IOL) in post-term pregnancies [ ]. In your article, you conclude that “births at GA 41+4 – 42+0 (“late group”) were associated with an increased risk of neonatal morbidity and birth complications compared with births at GA 41+0 – 41+3 weeks (“early group”)” (our parentheses). The intent of your analysis was to “determine the independent impact of GA” and thus “aid clinicians in deciding when to recommend IOL in late-term pregnancies”. It is well known that the rate of caesarean section (CS) in spontaneous labor is lower compared with the CS rate in IOL in the same gestational week [ ]. But this type of comparison does not provide relevant clinical information to the clinician and the pregnant woman in the decision making between IOL or expectant management [ ]. Likewise, it is fundamental that the intervention group only includes women with IOL in a comparison between IOL and expectant management. In your case, the intervention group or the early group is comprised of both women with IOL and women with a spontaneous labor. This means that the data from the early period will be influenced by the impact of the group of women with spontaneous labor. The regression analysis may adjust for but not exclude the influence on the outcome by the group of women with spontaneous labor. Thus, your method will inevitably bias against expectant management. Previously, the way to carry out an analysis of retrospective data with focus on the clinical aspect of IOL was recommended by Caughey et al [ ]. They compared IOL at the current gestational week versus expectant management with birth at a greater gestational week. Furthermore, using this method on Danish data no added risk of CS was found in IOL from GA 39 to 41 compared with expectant management [ ]. Analyzed in this way, your data may give valuable information on the influence of IOL versus expectant management in post-term pregnancies which is the clinical question.
Article
Objective Findings of the recent ARRIVE (A Randomized Trial of Induction Versus Expectant Management) trial, showing reduced cesarean risk with elective labor induction among low-risk nulliparous women at 39 weeks' gestation, have the potential to change interventional delivery practices but require examination in wider populations. The aim of this study was to identify whether term induction of labor was associated with reduced cesarean delivery risk among women with obesity, evaluating several maternal characteristics associated with obesity, induction, and cesarean risk. Study Design We studied administrative records for 66,280 singleton, term births to women with a body mass index ≥30, without a prior cesarean delivery, in New York City from 2008 to 2013. We examined elective inductions in 39 and 40 weeks' gestation and calculated adjusted risk ratios for cesarean delivery risk, stratified by parity and maternal age. We additionally evaluated medically indicated inductions at 37 to 40 weeks among women with obesity and diabetic or hypertensive disorders, comorbidities that are strongly associated with obesity. Results Elective induction of labor was associated with a 25% (95% confidence interval: 19–30%) lower adjusted risk of cesarean delivery as compared with expectant management at 39 weeks of gestation and no change in risk at 40 weeks. Patterns were similar when stratified by parity and maternal age. Risk reductions in week 39 were largest among women with a prior vaginal delivery. Women with comorbidities had reduced cesarean risk with early term induction and in 39 weeks. Conclusion Labor induction at 39 weeks was consistently associated with reduced risk of cesarean delivery among women with obesity regardless of parity, age, or comorbidity status. Cesarean delivery findings from induction trials at 39 weeks among low-risk nulliparous women may generalize more broadly across the U.S. obstetric population, with potentially larger benefit among women with a prior vaginal delivery. Key Points
Article
Background: Risks of stillbirth or neonatal death increase as gestation continues beyond term (around 40 weeks' gestation). It is unclear whether a policy of labour induction can reduce these risks. This Cochrane Review is an update of a review that was originally published in 2006 and subsequently updated in 2012 and 2018. Objectives: To assess the effects of a policy of labour induction at or beyond 37 weeks' gestation compared with a policy of awaiting spontaneous labour indefinitely (or until a later gestational age, or until a maternal or fetal indication for induction of labour arises) on pregnancy outcomes for the infant and the mother. Search methods: For this update, we searched Cochrane Pregnancy and Childbirth's Trials Register, ClinicalTrials.gov and the WHO International Clinical Trials Registry Platform (ICTRP) (17 July 2019), and reference lists of retrieved studies. Selection criteria: Randomised controlled trials (RCTs) conducted in pregnant women at or beyond 37 weeks, comparing a policy of labour induction with a policy of awaiting spontaneous onset of labour (expectant management). We also included trials published in abstract form only. Cluster-RCTs, quasi-RCTs and trials using a cross-over design were not eligible for inclusion in this review. We included pregnant women at or beyond 37 weeks' gestation. Since risk factors at this stage of pregnancy would normally require intervention, only trials including women at low risk for complications, as defined by trialists, were eligible. The trials of induction of labour in women with prelabour rupture of membranes at or beyond term were not considered in this review but are considered in a separate Cochrane Review. Data collection and analysis: Two review authors independently assessed trials for inclusion, assessed risk of bias and extracted data. Data were checked for accuracy. We assessed the certainty of evidence using the GRADE approach. Main results: In this updated review, we included 34 RCTs (reporting on over 21,000 women and infants) mostly conducted in high-income settings. The trials compared a policy to induce labour usually after 41 completed weeks of gestation (> 287 days) with waiting for labour to start and/or waiting for a period before inducing labour. The trials were generally at low to moderate risk of bias. Compared with a policy of expectant management, a policy of labour induction was associated with fewer (all-cause) perinatal deaths (risk ratio (RR) 0.31, 95% confidence interval (CI) 0.15 to 0.64; 22 trials, 18,795 infants; high-certainty evidence). There were four perinatal deaths in the labour induction policy group compared with 25 perinatal deaths in the expectant management group. The number needed to treat for an additional beneficial outcome (NNTB) with induction of labour, in order to prevent one perinatal death, was 544 (95% CI 441 to 1042). There were also fewer stillbirths in the induction group (RR 0.30, 95% CI 0.12 to 0.75; 22 trials, 18,795 infants; high-certainty evidence); two in the induction policy group and 16 in the expectant management group. For women in the policy of induction arms of trials, there were probably fewer caesarean sections compared with expectant management (RR 0.90, 95% CI 0.85 to 0.95; 31 trials, 21,030 women; moderate-certainty evidence); and probably little or no difference in operative vaginal births with induction (RR 1.03, 95% CI 0.96 to 1.10; 22 trials, 18,584 women; moderate-certainty evidence). Induction may make little or difference to perineal trauma (severe perineal tear: RR 1.04, 95% CI 0.85 to 1.26; 5 trials; 11,589 women; low-certainty evidence). Induction probably makes little or no difference to postpartum haemorrhage (RR 1.02, 95% CI 0.91 to 1.15, 9 trials; 12,609 women; moderate-certainty evidence), or breastfeeding at discharge (RR 1.00, 95% CI 0.96 to 1.04; 2 trials, 7487 women; moderate-certainty evidence). Very low certainty evidence means that we are uncertain about the effect of induction or expectant management on the length of maternal hospital stay (average mean difference (MD) -0.19 days, 95% CI -0.56 to 0.18; 7 trials; 4120 women; Tau² = 0.20; I² = 94%). Rates of neonatal intensive care unit (NICU) admission were lower (RR 0.88, 95% CI 0.80 to 0.96; 17 trials, 17,826 infants; high-certainty evidence), and probably fewer babies had Apgar scores less than seven at five minutes in the induction groups compared with expectant management (RR 0.73, 95% CI 0.56 to 0.96; 20 trials, 18,345 infants; moderate-certainty evidence). Induction or expectant management may make little or no difference for neonatal encephalopathy (RR 0.69, 95% CI 0.37 to 1.31; 2 trials, 8851 infants; low-certainty evidence, and probably makes little or no difference for neonatal trauma (RR 0.97, 95% CI 0.63 to 1.49; 5 trials, 13,106 infants; moderate-certainty evidence) for induction compared with expectant management. Neurodevelopment at childhood follow-up and postnatal depression were not reported by any trials. In subgroup analyses, no differences were seen for timing of induction (< 40 versus 40-41 versus > 41 weeks' gestation), by parity (primiparous versus multiparous) or state of cervix for any of the main outcomes (perinatal death, stillbirth, NICU admission, caesarean section, operative vaginal birth, or perineal trauma). Authors' conclusions: There is a clear reduction in perinatal death with a policy of labour induction at or beyond 37 weeks compared with expectant management, though absolute rates are small (0.4 versus 3 deaths per 1000). There were also lower caesarean rates without increasing rates of operative vaginal births and there were fewer NICU admissions with a policy of induction. Most of the important outcomes assessed using GRADE had high- or moderate-certainty ratings. While existing trials have not yet reported on childhood neurodevelopment, this is an important area for future research. The optimal timing of offering induction of labour to women at or beyond 37 weeks' gestation needs further investigation, as does further exploration of risk profiles of women and their values and preferences. Offering women tailored counselling may help them make an informed choice between induction of labour for pregnancies, particularly those continuing beyond 41 weeks - or waiting for labour to start and/or waiting before inducing labour.
Article
We are grateful for the opportunity to reply to the comments to our paper on maternal age and risk on cesarean section (CS) in induced labor at term in the Nordic countries (1) by Ole Bredahl Rasmussen (2). Rasmussen states that we conclude that women should be informed about a higher risk of CS if they have their labor induced compared with spontaneous labor. He underlines why a direct comparison of risk of CS risk in women in spontaneous labor with women having labor induced at any given gestational age around term, is irrelevant in a clinical setting for the patient (3). We completely agree with this reasoning. Our paper is focusing on the increasing risk of CS with increasing age among women having labor induced.
Article
Background: Elective induction of labor at 39 weeks among low-risk nulliparous women has reduced the chance of cesarean and other adverse maternal and perinatal outcomes in a randomized trial, although its clinical effectiveness in nonresearch settings remains uncertain. Objective: To perform a systematic review of observational studies that compared elective induction of labor at 39 weeks among nulliparous women with expectant management and to use meta-analytic techniques to estimate the association of elective induction with cesarean delivery, as well as other maternal and perinatal outcomes. Study design: Studies were eligible for this meta-analysis only if they: (1) were observational; (2) compared women undergoing labor induction at 39 weeks with women undergoing expectant management beyond that gestational age; (3) included women in the induction group only if they had no other indication for labor induction at 39 weeks; and (4) provided data specifically for nulliparous women. The predefined primary outcome was cesarean delivery, and secondary outcomes representing other maternal and perinatal morbidities also were evaluated. Outcome data from different studies were combined to estimate pooled relative risks with 95% confidence intervals using random-effects models. Results: Of 375 studies identified by the initial search, 6 cohort studies, which included 66,019 women undergoing elective labor induction at 39 weeks and 584,390 undergoing expectant management, met inclusion criteria. Elective induction of labor at 39 weeks was associated with a significantly lower frequency of cesarean delivery (26.4% vs 29.1%; relative risk, 0.83; 95% confidence interval, 0.74-0.93), as well as of peripartum infection (2.8% vs 5.2%; relative risk, 0.53; 95% confidence interval, 0.39-0.72). Neonates of women in the induction group were less likely to have respiratory morbidity (0.7% vs 1.5%; relative risk, 0.71; 95% confidence interval, 0.59-0.85); meconium aspiration syndrome (0.7% vs 3.0%; relative risk, 0.49; 95% confidence interval, 0.26-0.92); and neonatal intensive care unit admission (3.5% vs 5.5%; relative risk, 0.80; 95% confidence interval, 0.72-0.88). There also was a lower risk of perinatal mortality (0.04% vs 0.2%; relative risk, 0.27; 95% confidence interval, 0.09-0.76). Conclusion: This meta-analysis of 6 cohort studies demonstrates that elective induction of labor at 39 weeks, compared with expectant management beyond that gestational age, was associated with a significantly lower risk of cesarean delivery, maternal peripartum infection, and perinatal adverse outcomes, including respiratory morbidity, intensive care unit admission, and mortality.
Article
Introduction: There is an ongoing debate on the optimal time of labor induction to reduce the risks associated with prolonged pregnancy MATERIAL AND METHODS: Registry-based study of 212,716 term, singleton cephalic deliveries between 2006 and 2012 in Finland comparing the outcomes of labor induction to those of expectant management in five three-day gestational age periods between 40 and 42 weeks (Group 1:40+0-40+2; 2:40+3-40+5;3: 40+6-41+1;4: 41+2-41+4;5: 41+5-42+0). Using Poisson regression, induced deliveries in each of the gestational age periods were compared to all ongoing pregnancies. Propensity score matching was applied to reduce confounding by indication RESULTS: In the gestational age groups 1-2 labor induction significantly decreased the risk meconium aspiration syndrome (RR 0.40, 95% CI 0.18-0.91, RR 0.44, 95% CI 0.21-0.91) but in contrast, increased the risk for prolonged hospitalization of a neonate (RR 1.30, 95% CI 1.10-1.54 and RR 1.23, 95% CI 1.03-1.47). In the groups 3-4, labor induction significantly increased the risk for emergency cesarean section (RR 1.17, 95% CI 1.06-1.28 and RR 1.19, 95% CI 1.09-1.29) still reducing the risk for meconium aspiration syndrome. In the group 5, labor induction did not affect the risk for any of the studied outcomes (operative delivery, obstetric trauma, neonatal mortality, respirator treatment, Apgar <7) CONCLUSIONS: Propensity score matching is a novel approach to studying the effect of labor induction. It highlighted the conflicting maternal and neonatal risks and benefits of the intervention and enforced expectant management as a valid option, at least until close to 42 weeks. This article is protected by copyright. All rights reserved.
Article
Background: Induction of labor (IOL) is a common obstetric intervention, yet its impact on intervention rates and perinatal outcomes is conflicting. Aims: To evaluate the impact of IOL on intrapartum intervention rates and perinatal outcomes in women with singleton pregnancies at term. Material and methods: This was a retrospective, cross-sectional study of term singleton deliveries at the Mater Mother's Hospital in Brisbane, Australia in 2007-2013. The IOL cohort was compared to an expectantly managed group. Results: Of the final cohort (44 698 women), 64.4% had expectant management and 35.6% had IOL. Multivariate analyses showed that IOL was associated with lower odds of spontaneous vaginal delivery from ≥37 weeks gestation. The risk of emergency caesarean for non-reassuring fetal status was also higher in the IOL cohort at 40 and 41 weeks gestation. For women who were managed expectantly, the highest rate of spontaneous vaginal delivery and the lowest rate of emergency caesareans occurred at 39 weeks gestation. For women who underwent IOL, the nadir emergency caesarean rate and the highest spontaneous vaginal delivery rate was also at 39 weeks. Rates of neonatal intensive car unit admission were higher in the IOL group at 37 weeks (adjusted odds ratio (aOR) 3.11, 95% CI: 2.62-3.68) and 38 weeks (aOR 1.78, 95% CI: 1.55-2.04) and lower at >42 weeks (OR 0.35, 95% CI: 0.14-0.81) respectively. Conclusion: IOL compared to expectant management is associated with lower spontaneous vaginal delivery rates and increased risk of emergency caesarean for intrapartum fetal compromise with broadly comparable perinatal outcomes.
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Article
Background: Induction of labour is common, and cesarean delivery is regarded as its major complication. We conducted a systematic review and meta-analysis to investigate whether the risk of cesarean delivery is higher or lower following labour induction compared with expectant management. Methods: We searched 6 electronic databases for relevant articles published through April 2012 to identify randomized controlled trials (RCTs) in which labour induction was compared with placebo or expectant management among women with a viable singleton pregnancy. We assessed risk of bias and obtained data on rates of cesarean delivery. We used regression analysis techniques to explore the effect of patient characteristics, induction methods and study quality on risk of cesarean delivery. Results: We identified 157 eligible RCTs (n = 31,085). Overall, the risk of cesarean delivery was 12% lower with labour induction than with expectant management (pooled relative risk [RR] 0.88, 95% confidence interval [CI] 0.84-0.93; I(2) = 0%). The effect was significant in term and post-term gestations but not in preterm gestations. Meta-regression analysis showed that initial cervical score, indication for induction and method of induction did not alter the main result. There was a reduced risk of fetal death (RR 0.50, 95% CI 0.25-0.99; I(2) = 0%) and admission to a neonatal intensive care unit (RR 0.86, 95% CI 0.79-0.94), and no impact on maternal death (RR 1.00, 95% CI 0.10-9.57; I(2) = 0%) with labour induction. Interpretation: The risk of cesarean delivery was lower among women whose labour was induced than among those managed expectantly in term and post-term gestations. There were benefits for the fetus and no increased risk of maternal death.
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Elective induction of labor is a controversial topic. An observed relationship between elective induction and primary cesarean delivery has been of particular concern, and has guided much of the research to date on both indicated and elective induction of labor. However, it is unclear whether elective induction of labor actually increases the risk of cesarean delivery. This chapter focuses on key method issues to consider in studies of elective induction of labor. We first identify methodological concerns with the existing literature and discuss each in turn. We then review existing evidence about the relationship between elective induction and cesarean delivery.
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Aggregate databases are increasingly being used to evaluate appropriateness of care, and, for cesarean sections, Anderson and Lomas' International Classification of Diseases, 9th Revision (ICD-9), coding hierarchy is a widely used tool. The aim of this study was to assess the validity of the hierarchy and expand its applicability to repeat cesareans. Hospital records of 1885 singleton cesareans were reviewed. Clinical indications and ICD-9 hierarchical codes were concordant for 83% of primary and 86% of repeat cesareans; modification allowed elective repeat cesareans to be distinguished from indicated procedures. The Anderson and Lomas ICD-9 hierarchy is a valid tool for assessing indications for cesarean. The current modification improves its clinical utility and expands its application to repeat procedures.
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To estimate the association between elective induction of labor and cesarean section in low-risk parous women, and to assess whether the association is influenced by induction method. Cohort study. University hospital in Sweden. Parous women without pregnancy complications or previous cesarean section, and with a planned vaginal term (37–41 weeks), singleton birth, in vertex position were included. Information was collected from a local database containing prospectively entered antenatal and delivery data. Odds ratios for cesarean section were calculated using generalized estimating equations logistic regression and adjusted for parity, maternal age, gestational length, birthweight, use of epidural anesthesia and year of birth. Emergency cesarean section. Among 7973 pregnancies that fulfilled the inclusion criteria, 343 (4%) had an elective induction of labor. Intravenous oxytocin was administered in 5% of these inductions, amniotomy was performed in 62%, and a cervical ripening agent was used in 33%. Electively induced labor more than doubled the risk of cesarean section compared with spontaneous labor onset (OR 2.5, 95% CI 1.4–4.2) and this risk was more than tripled when cervical ripening was used (OR 3.6, 95% CI 1.7–7.6). In low-risk parous women, electively induced labor has an increased risk of emergency cesarean section compared with spontaneous onset labor. This risk increase is more pronounced if cervical ripening agents are required. Women need to be counseled about these risks before elective induction of delivery is decided.
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Background: Numerous study results vary when analyzing the relationship between labor induction and the likelihood of cesarean delivery; and few have accounted for the multiple influences of maternal sociodemographic characteristics combined with the provider and hospital in subsequent birth outcomes such as cesarean section. Objective: This study evaluated the likelihood of cesarean birth following labor induction while accounting for maternal, hospital, and provider characteristics. Methods: A cross-sectional retrospective descriptive design using secondary data was employed to determine what variation in cesarean births was due to differences of hospitals, providers, and patients using the Quality Health Outcomes Model (QHOM). Data were partitioned by primiparous and multiparous women. The individual demographic, system, and provider outcomes in all hospitals and single birth center for Maricopa County in 2005 (N=62,816) were analyzed, using both random effects and fixed effects models. Results: For primiparous women, an increased likelihood of cesarean births was associated with medical inductions, maternal age, being Black, and the number of prenatal visits; and less likely in teaching hospitals and women with higher educational attainment. In multiparous women, cesarean births were associated with increased maternal age and medical inductions; and less likely in for-profit hospitals and following elective induction. Discussion: Labor inductions were associated with an increased likelihood of cesarean sections based on parity, age, race, number of prenatal visits, education, and hospital teaching status and ownership. Because the QHOM emphasizes multiple contextual variables that influence the delivery and outcomes of care, it can prove ideal for the study of birth outcomes following interventions such as the induction of labor. Clinical Relevance: Nurses should be well educated about the risks of elective labor induction prior to term gestation and “elective” cesarean birth.
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This report presents 2009 data on U.S. births according to a wide variety of characteristics. Data are presented for maternal characteristics including age, live-birth order, race and Hispanic origin, marital status, hypertension during pregnancy, attendant at birth, method of delivery, and infant characteristics (period of gestation, birthweight, and plurality). Birth and fertility rates by age, live-birth order, race and Hispanic origin, and marital status also are presented. Selected data by mother's state of residence are shown, as well as birth rates by age and race of father. Trends in fertility patterns and maternal and infant characteristics are described and interpreted. Descriptive tabulations of data reported on the birth certificates of the 4.13 million births that occurred in 2009 are presented. Denominators for population-based rates are postcensal estimates derived from the U.S. 2000 census. The number of births declined to 4,130,665 in 2009, 3 percent less than in 2008. The general fertility rate declined 3 percent to 66.7 per 1,000 women aged 15-44 years. The teenage birth rate fell 6 percent to 39.1 per 1,000. Birth rates for women in each 5-year age group from 20 through 39 years declined, but the rate for women 40-44 years continued to rise. The total fertility rate (estimated number of births over a woman's lifetime) was down 4 percent to 2,007.0 per 1,000 women. The number and rate of births to unmarried women declined, whereas the percentage of nonmarital births increased slightly to 41.0. The cesarean delivery rate rose again, to 32.9 percent. The preterm birth rate declined to 12.18 percent; the low birthweight rate was stable at 8.16 percent. The twin birth rate increased to 33.2 per 1,000; the triplet and higher-order multiple birth rate rose 4 percent to 153.5 per 100,000.
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To determine neonatal outcomes (perinatal mortality and special care unit admission) and maternal outcomes (mode of delivery, delivery complications) of elective induction of labour compared with expectant management. Retrospective cohort study using an unselected population database. Consultant and midwife led obstetric units in Scotland 1981-2007. 1,271,549 women with singleton pregnancies of 37 weeks or more gestation. Outcomes of elective induction of labour (induction of labour with no recognised medical indication) at 37, 38, 39, 40, and 41 weeks' gestation compared with those of expectant management (continuation of pregnancy to either spontaneous labour, induction of labour or caesarean section at a later gestation). Extended perinatal mortality, mode of delivery, postpartum haemorrhage, obstetric anal sphincter injury, and admission to a neonatal or special care baby unit. Outcomes were adjusted for age at delivery, parity, year of birth, birth weight, deprivation category, and, where appropriate, mode of delivery. At each gestation between 37 and 41 completed weeks, elective induction of labour was associated with a decreased odds of perinatal mortality compared with expectant management (at 40 weeks' gestation 0.08% (37/44,764) in the induction of labour group versus 0.18% (627/350,643) in the expectant management group; adjusted odds ratio 0.39, 99% confidence interval 0.24 to 0.63), without a reduction in the odds of spontaneous vertex delivery (at 40 weeks' gestation 79.9% (35,775/44,778) in the induction of labour group versus 73.7% (258,665/350,791) in the expectant management group; adjusted odds ratio 1.26, 1.22 to 1.31). Admission to a neonatal unit was, however, increased in association with elective induction of labour at all gestations before 41 weeks (at 40 weeks' gestation 8.0% (3605/44,778) in the induction of labour group compared with 7.3% (25,572/350,791) in the expectant management group; adjusted odds ratio 1.14, 1.09 to 1.20). Although residual confounding may remain, our findings indicate that elective induction of labour at term gestation can reduce perinatal mortality in developed countries without increasing the risk of operative delivery.
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The purpose of this review is to describe how Paralympians can prepare for the 2014 Paralympic Games through mental skill use. A search of adapted physical activity, sport psychology, and disability-specific journals was conducted along with electronic databases (eg, ArticleFirst) using the terms sport psychology, Olympics, Paralympics, psychological and mental preparation and skills, imagery, visualization, self-talk, anxiety, confidence, and performance enhancement. Reference lists from relevant articles were then used to continue the search. No constraining dates were used. A review of the results from both qualitative and quantitative research on Paralympians, Olympians, and elite-level athletes suggests that mental preparation and mental skill development can help Paralympians enhance their performances. Sport psychologists can help Paralympians develop mental skills to manage the unique stressors of the Paralympics to increase the odds of having superior performances.
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To assess the risk for emergency cesarean section among women in whom labor was induced in gestational week ≥41 and to evaluate if parity and mode of induction affected this association. Hospital-based retrospective cohort study. Singleton pregnancies delivered after ≥41 gestational weeks at Danderyd Hospital, Stockholm, Sweden, during 2002-2006. Of 23 030 singleton pregnancies meeting the entry criteria, 881 were induced with a Bishop score of <7. Obstetric outcome was assessed through linkage with the Swedish Medical Birth Registry and a local obstetrical database containing information from patients' medical files. Results were adjusted for body mass index, age and the use of epidural analgesia. Risk for emergency cesarean section. Among women who were induced, the proportions delivered by emergency cesarean section were 42% for nulliparous and 14% for multiparous. Compared to spontaneous onset, this corresponded to a more than threefold increase in risk for nulliparous women (OR 3.34, 95%CI 2.77-4.04) and an almost twofold increase in risk for multiparous women (OR 1.94, 95%CI 1.24-3.02). There was no significant difference in risk for emergency cesarean section between the two methods of induction (PGE(2) and transcervical catheter). Compared to spontaneous onset of delivery, induction of labor is associated with an increased risk for emergency cesarean section both among nulliparous and multiparous women. When labor is induced, the high risk for emergency cesarean must be kept in mind.
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To compare induction of labor and expectant management by gestational week with regard to the need for cesarean section (CS) in labor. Cohort study. National study based on the Danish Birth Registry. Aggregated data from 230 528 deliveries from 2004 until mid-year 2009. Women with cesarean section before labor, previous cesarean, preterm birth, breech presentation, multiple pregnancy and specified medical illnesses in pregnancy were excluded. We compared by gestational week nulliparous and parous women who were either induced or had expectant management until later spontaneous or induced labor. For each of five comparisons, we conducted multivariable logistic regression analysis, controlling for body mass index, age, smoking in pregnancy and use of epidural analgesia during labor. Rate of CS in labor. From gestational week 39 and thereafter, there was no difference with regard to CS rates in labor among nulliparous and parous women when comparing women with induced labor and those women who waited for a later labor, either induced or spontaneous. The odds ratios (with confidence intervals) for CS in labor in nulliparous women were 0.99 (0.84-1.17), 1.16 (1.04-1.30), 1.04 (0.94-1.15), 1.00 (0.92-1.10) and 0.97 (0.88-1.07) for weeks 37-41, respectively. For parous women the corresponding figures were 1.72 (1.35-2.20), 1.27 (1.04-1.55), 1.15 (0.95-1.39), 1.18 (0.99-1.40) and 1.07 (0.87-1.32), respectively. Induction of labor provides a sound tool when counseling a woman either going past term or presenting with a problem, even if it is not a severe medical illness.
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To compare the effect of induction of labour with a policy of expectant monitoring for intrauterine growth restriction near term. Multicentre randomised equivalence trial (the Disproportionate Intrauterine Growth Intervention Trial At Term (DIGITAT)). Eight academic and 44 non-academic hospitals in the Netherlands between November 2004 and November 2008. Pregnant women who had a singleton pregnancy beyond 36+0 weeks' gestation with suspected intrauterine growth restriction. Induction of labour or expectant monitoring. The primary outcome was a composite measure of adverse neonatal outcome, defined as death before hospital discharge, five minute Apgar score of less than 7, umbilical artery pH of less than 7.05, or admission to the intensive care unit. Operative delivery (vaginal instrumental delivery or caesarean section) was a secondary outcome. Analysis was by intention to treat, with confidence intervals calculated for the differences in percentages or means. 321 pregnant women were randomly allocated to induction and 329 to expectant monitoring. Induction group infants were delivered 10 days earlier (mean difference -9.9 days, 95% CI -11.3 to -8.6) and weighed 130 g less (mean difference -130 g, 95% CI -188 g to -71 g) than babies in the expectant monitoring group. A total of 17 (5.3%) infants in the induction group experienced the composite adverse neonatal outcome, compared with 20 (6.1%) in the expectant monitoring group (difference -0.8%, 95% CI -4.3% to 3.2%). Caesarean sections were performed on 45 (14.0%) mothers in the induction group and 45 (13.7%) in the expectant monitoring group (difference 0.3%, 95% CI -5.0% to 5.6%). In women with suspected intrauterine growth restriction at term, we found no important differences in adverse outcomes between induction of labour and expectant monitoring. Patients who are keen on non-intervention can safely choose expectant management with intensive maternal and fetal monitoring; however, it is rational to choose induction to prevent possible neonatal morbidity and stillbirth. International Standard Randomised Controlled Trial number ISRCTN10363217.
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The rates of induction of labor and elective induction of labor are increasing. Whether elective induction of labor improves outcomes or simply leads to greater complications and health care costs is commonly debated in the literature. To compare the benefits and harms of elective induction of labor and expectant management of pregnancy. MEDLINE (through February 2009), Web of Science, CINAHL, Cochrane Central Register of Controlled Trials (through March 2009), bibliographies of included studies, and previous systematic reviews. Experimental and observational studies of elective induction of labor reported in English. Two authors abstracted study design; patient characteristics; quality criteria; and outcomes, including cesarean delivery and maternal and neonatal morbidity. Of 6117 potentially relevant articles, 36 met inclusion criteria: 11 randomized, controlled trials (RCTs) and 25 observational studies. Overall, expectant management of pregnancy was associated with a higher odds ratio (OR) of cesarean delivery than was elective induction of labor (OR, 1.22 [95% CI, 1.07 to 1.39]; absolute risk difference, 1.9 percentage points [CI, 0.2 to 3.7 percentage points]) in 9 RCTs. Women at or beyond 41 completed weeks of gestation who were managed expectantly had a higher risk for cesarean delivery (OR, 1.21 [CI, 1.01 to 1.46]), but this difference was not statistically significant in women at less than 41 completed weeks of gestation (OR, 1.73 [CI, 0.67 to 4.5]). Women who were expectantly managed were more likely to have meconium-stained amniotic fluid than those who were electively induced (OR, 2.04 [CI, 1.34 to 3.09]). Limitations: There were no recent RCTs of elective induction of labor at less than 41 weeks of gestation. The 2 studies conducted at less than 41 weeks of gestation were of poor quality and were not generalizable to current practice. RCTs suggest that elective induction of labor at 41 weeks of gestation and beyond is associated with a decreased risk for cesarean delivery and meconium-stained amniotic fluid. There are concerns about the translation of these findings into actual practice; thus, future studies should examine elective induction of labor in settings where most obstetric care is provided.
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Robust evidence to direct management of pregnant women with mild hypertensive disease at term is scarce. We investigated whether induction of labour in women with a singleton pregnancy complicated by gestational hypertension or mild pre-eclampsia reduces severe maternal morbidity. We undertook a multicentre, parallel, open-label randomised controlled trial in six academic and 32 non-academic hospitals in the Netherlands between October, 2005, and March, 2008. We enrolled patients with a singleton pregnancy at 36-41 weeks' gestation, and who had gestational hypertension or mild pre-eclampsia. Participants were randomly allocated in a 1:1 ratio by block randomisation with a web-based application system to receive either induction of labour or expectant monitoring. Masking of intervention allocation was not possible. The primary outcome was a composite measure of poor maternal outcome--maternal mortality, maternal morbidity (eclampsia, HELLP syndrome, pulmonary oedema, thromboembolic disease, and placental abruption), progression to severe hypertension or proteinuria, and major post-partum haemorrhage (>1000 mL blood loss). Analysis was by intention to treat and treatment effect is presented as relative risk. This study is registered, number ISRCTN08132825. 756 patients were allocated to receive induction of labour (n=377 patients) or expectant monitoring (n=379). 397 patients refused randomisation but authorised use of their medical records. Of women who were randomised, 117 (31%) allocated to induction of labour developed poor maternal outcome compared with 166 (44%) allocated to expectant monitoring (relative risk 0.71, 95% CI 0.59-0.86, p<0.0001). No cases of maternal or neonatal death or eclampsia were recorded. Induction of labour is associated with improved maternal outcome and should be advised for women with mild hypertensive disease beyond 37 weeks' gestation. ZonMw.
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Aggregate databases are increasingly being used to evaluate appropriateness of care, and, for cesarean sections, Anderson and Lomas' International Classification of Diseases, 9th Revision (ICD-9), coding hierarchy is a widely used tool. The aim of this study was to assess the validity of the hierarchy and expand its applicability to repeat cesareans. Hospital records of 1885 singleton cesareans were reviewed. Clinical indications and ICD-9 hierarchical codes were concordant for 83% of primary and 86% of repeat cesareans; modification allowed elective repeat cesareans to be distinguished from indicated procedures. The Anderson and Lomas ICD-9 hierarchy is a valid tool for assessing indications for cesarean. The current modification improves its clinical utility and expands its application to repeat procedures.
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To quantify the risk and risk factors for cesarean delivery associated with medical and elective induction of labor in nulliparous women. A prospective cohort study was performed in nulliparous women at term with vertex singleton gestations who had labor induced at 2 obstetrical centers. Medical and elective indications and Bishop scores were recorded before labor induction. Obstetric and neonatal data were analyzed and compared with the results in women with a spontaneous onset of labor. Data were analyzed using univariate and multivariable regression modeling. A total of 1,389 women were included in the study. The cesarean delivery rate was 12.0% in women with a spontaneous onset of labor (n = 765), 23.4% in women undergoing labor induction for medical reasons (n = 435) (unadjusted odds ratio [OR] 2.24; 95% confidence interval [CI] 1.64-3.06), and 23.8% in women whose labor was electively induced (n = 189) (unadjusted OR 2.29; 95% CI 1.53-3.41). However, after adjusting for the Bishop score at admission, no significant differences in cesarean delivery rates were found among the 3 groups. A Bishop score of 5 or less was a predominant risk factor for a cesarean delivery in all 3 groups (adjusted OR 2.32; 95% CI 1.66-3.25). Other variables with significantly increased risk for cesarean delivery included maternal age of 30 years or older, body mass index of 31 or higher, use of epidural analgesia during the first stage of labor, and birth weight of 3,500 g or higher. In both induction groups, more newborns required neonatal care, more mothers needed a blood transfusion, and the maternal hospital stay was longer. Compared with spontaneous onset of labor, medical and elective induction of labor in nulliparous women at term with a single fetus in cephalic presentation is associated with an increased risk of cesarean delivery, predominantly related to an unfavorable Bishop score at admission. II-2.
Article
Background: The rates of induction of labor and elective induction of labor are increasing. Whether elective induction of labor improves outcomes or simply leads to greater complications and health care costs is commonly debated in the literature. Purpose: To compare the benefits and harms of elective induction of labor and expectant management of pregnancy. Data Sources: MEDLINE (through February 2009), Web of Science, CINAHL, Cochrane Central Register of Controlled Trials (through March 2009), bibliographies of included studies, and previous systematic reviews. Study Selection: Experimental and observational studies of elective induction of labor reported in English. Data Extraction: Two authors abstracted study design; patient characteristics; quality criteria; and outcomes, including cesarean delivery and maternal and neonatal morbidity. Data Synthesis: Of 6117 potentially relevant articles, 36 met inclusion criteria: 11 randomized, controlled trials (RCTs) and 25 observational studies. Overall, expectant management of pregnancy was associated with a higher odds ratio (OR) of cesarean delivery than was elective induction of labor (OR, 1.22 [95% CI, 1.07 to 1.39]; absolute risk difference, 1.9 percentage points [CI, 0.2 to 3.7 percentage points]) in 9 RCTs. Women at or beyond 41 completed weeks of gestation who were managed expectantly had a higher risk for cesarean delivery (OR, 1.21 [CI, 1.01 to 1.46]), but this difference was not statistically significant in women at less than 41 completed weeks of gestation (OR, 1.73 [CI, 0.67 to 4.5]). Women who were expectantly managed were more likely to have meconium-stained amniotic fluid than those who were electively induced (OR, 2.04 [Cl, 1.34 to 3.09]). Limitations: There were no recent RCTs of elective induction of labor at less than 41 weeks of gestation. The 2 studies conducted at less than 41 weeks of gestation were of poor quality and were not generalizable to current practice. Conclusion: RCTs suggest that elective induction of labor at 41 weeks of gestation and beyond is associated with a decreased risk for cesarean delivery and meconium-stained amniotic fluid. There are concerns about the translation of these findings into actual practice; thus, future studies should examine elective induction of labor in settings where most obstetric care is provided.
Article
To test the association of elective induction of labor at term compared with expectant management and maternal and neonatal outcomes. This was a retrospective cohort study of all deliveries without prior cesarean delivery in California in 2006 using linked hospital discharge and vital statistics data. We compared elective induction at each term gestational age (37-40 weeks) as defined by The Joint Commission with expectant management in vertex, nonanomalous, singleton deliveries. We used multivariable logistic regression to test the association of elective induction and cesarean delivery, operative vaginal delivery, maternal third- or fourth-degree lacerations, perinatal death, neonatal intensive care unit admission, respiratory distress, shoulder dystocia, hyperbilirubinemia, and macrosomia (birth weight greater than 4,000 g) at each gestational week, stratified by parity. The cesarean delivery rate was 16%, perinatal mortality was 0.2%, and neonatal intensive care unit admission was 6.2% (N=362,154). The odds of cesarean delivery were lower among women with elective induction compared with expectant management across all gestational ages and parity (37 weeks [odds ratio (OR) 0.44, 95% confidence interval (CI) 0.34-0.57], 38 weeks [OR 0.43, 95% CI 0.38-0.50], 39 weeks [OR 0.46, 95% CI 0.41-0.52], 40 weeks [OR 0.57, CI 0.50-0.65]). Elective induction was not associated with increased odds of severe lacerations, operative vaginal delivery, perinatal death, neonatal intensive care unit admission, respiratory distress, shoulder dystocia, or macrosomia at any term gestational age. Elective induction was associated with increased odds of hyperbilirubinemia at 37 and 38 weeks of gestation and shoulder dystocia at 39 weeks of gestation. Elective induction of labor is associated with decreased odds of cesarean delivery when compared with expectant management. LEVEL OF EVIDENCE:: II.
Article
Objective: We sought to examine the association of labor induction and perinatal outcomes. Study design: This was a retrospective cohort study of low-risk nulliparous women with term, live births. Women who had induction at a given gestational age (eg, 39 weeks) were compared to delivery at a later gestation (eg, 40, 41, or 42 weeks). Results: Compared to delivery at a later gestational age, those induced at 39 weeks had a lower risk of cesarean (adjusted odds ratio [aOR], 0.90; 95% confidence interval [CI], 0.88-0.91) and labor dystocia (aOR, 0.88; 95% CI, 0.84-0.94). Their neonates had lowered risk of having 5-minute Apgar <7 (aOR, 0.81; 95% CI, 0.72-0.92), meconium aspiration syndrome (aOR, 0.30; 95% CI, 0.19-0.48), and admission to neonatal intensive care unit (aOR, 0.87; 95% CI, 0.78-0.97). Similar findings were seen for women who were induced at 40 weeks compared to delivery later. Conclusion: Induction of labor in low-risk women at term is not associated with increased risk of cesarean delivery compared to delivery later.
Article
Approximately 1 in 4 women in the United States are induced, with up to 1 in 10-12 being induced for elective reasons. National guidelines by the American College of Obstetricians and Gynecologists, the Society of Obstetricians Gynaecologists of Canada, and the Royal College of Obstetricians and Gynaecologists list 21 indications for inductions; however, all 3 concur in only 14% women (3 of 21). An induction should be considered appropriate if it meets the following 4 criteria: (1) concordant with women's autonomous informed decisions and desideratum; (2) optimizes maternal-fetal outcomes, including psychological maternal well-being; (3) congruous with evidence-based medicine; and (4) cost-effective. A meta-analysis of 22 randomized trials noted that membrane sweeping reduces the likelihood of induction. Implementing policies to prevent elective induction at 37-38 weeks provides conflicting results about the rate of macrosomia and stillbirth at early term. We argue that a well-designed randomized controlled trial, with adequate power to demonstrate whether prohibiting elective induction increases the rate of stillbirth or complications such as macrosomia, is warranted. Patient education during their prenatal course is a promising strategy to decrease the rate of induction.
Article
Background: As a pregnancy continues beyond term the risks of babies dying inside the womb or in the immediate newborn period increase. Whether a policy of labour induction at a predetermined gestational age can reduce this increased risk is the subject of this review. Objectives: To evaluate the benefits and harms of a policy of labour induction at term or post-term compared with awaiting spontaneous labour or later induction of labour. Search methods: We searched the Cochrane Pregnancy and Childbirth Group's Trials Register (31 March 2012). Selection criteria: Randomised controlled trials conducted in women at or beyond term. The eligible trials were those comparing a policy of labour induction with a policy of awaiting spontaneous onset of labour. Cluster-randomised trials and cross-over trials are not included. Quasi-random allocation schemes such as alternation, case record numbers or open random-number lists were not eligible. Data collection and analysis: Two review authors independently assessed trials for inclusion. Two review authors independently assessed trial quality and extracted data. Data were checked for accuracy. Outcomes are analysed in two main categories: gestational age and cervix status. Main results: We included 22 trials reporting on 9383 women. The trials were generally at moderate risk of bias.Compared with a policy of expectant management, a policy of labour induction was associated with fewer (all-cause) perinatal deaths: risk ratio (RR) 0.31, 95% confidence interval (CI) 0.12 to 0.88; 17 trials, 7407 women. There was one perinatal death in the labour induction policy group compared with 13 perinatal deaths in the expectant management group. The number needed to treat to benefit (NNTB) with induction of labour in order to prevent one perinatal death was 410 (95% CI 322 to 1492).For the primary outcome of perinatal death and most other outcomes, no differences between timing of induction subgroups were seen; the majority of trials adopted a policy of induction at 41 completed weeks (287 days) or more.Fewer babies in the labour induction group had meconium aspiration syndrome (RR 0.50, 95% CI 0.34 to 0.73; eight trials, 2371 infants) compared with a policy of expectant management. There was no statistically significant difference between the rates of neonatal intensive care unit (NICU) admission for induction compared with expectant management (RR 0.90, 95% CI 0.78 to 1.04; 10 trials, 6161 infants). For women in the policy of induction arms of trials, there were significantly fewer caesarean sections compared with expectant management in 21 trials of 8749 women (RR 0.89, 95% CI 0.81 to 0.97). Authors' conclusions: A policy of labour induction compared with expectant management is associated with fewer perinatal deaths and fewer caesarean sections. Some infant morbidities such as meconium aspiration syndrome were also reduced with a policy of post-term labour induction although no significant differences in the rate of NICU admission were seen.However, the absolute risk of perinatal death is small. Women should be appropriately counselled in order to make an informed choice between scheduled induction for a post-term pregnancy or monitoring without induction (or delayed induction).
Article
To evaluate maternal and neonatal outcomes associated with birth at term by week of gestational age and also by onset of labor. Cohort study. A state-wide perinatal outcome database. 28,626 women with spontaneous onset of labor, induction of labor for recognized indications and induction of labor for non-recognized indications. Cohort study utilizing a validated dataset comparing outcomes with type of onset of labor using a log binomial model. Cesarean section, assisted vaginal birth, important measures of maternal and neonatal morbidity. Induction of labor for non-recognized indications was associated with a significantly increased risk of a range of outcomes, including cesarean section (RR 1.67, 95% CI 1.55-1.80). The lowest risk of adverse maternal and infant outcome occurred with birth between 38 and 39 weeks and with the spontaneous onset of labor. Induction of labor for non-recognized indications at term is associated with an increased risk of adverse outcomes. Caution is warranted with a liberal policy of induction of labor at term in an otherwise uncomplicated pregnancy.
Article
The growing public health awareness of prematurity and its complications has prompted careful evaluation of the timing of deliveries by clinicians and hospitals. Preterm birth is associated with significant morbidity and mortality, and affects more than half a million births in the United States each year. In some situations, however, a late-preterm or early-term birth is the optimal outcome for the mother, child, or both owing to conditions that can result in worse outcomes if pregnancy is allowed to continue. These conditions may be categorized as placental, maternal, or fetal, including conditions such as placenta previa, preeclampsia, and multiple gestations. Some risks associated with early delivery are common to all conditions, including prematurity-related morbidities (eg, respiratory distress syndrome and intraventricular hemorrhage) as well as maternal intrapartum morbidities such as failed induction and cesarean delivery. However, when continuation of the pregnancy is associated with more risks such as hemorrhage, uterine rupture, and stillbirth, preterm delivery maybe indicated. In February 2011, the Eunice Kennedy Shriver National Institute of Child Health and Human Development and the Society for Maternal-Fetal Medicine held a workshop titled "Timing of Indicated Late Preterm and Early Term Births." The goal of the workshop was to synthesize the available information regarding conditions that may result in medically indicated late-preterm and early-term births to determine the potential risks and benefits of delivery compared with continued pregnancy, determine the optimal gestational age for delivery of affected pregnancies when possible, and inform future research regarding these issues. Based on available data and expert opinion, optimal timing for delivery for specific conditions was determined by consensus.
Article
To investigate risk factors associated with postterm pregnancy and cesarean delivery following labor induction. Population-based cohort study. Sweden. From the Swedish Medical Birth Register, a total of 1,176,131 singletons births from gestational week 37 and onwards, between 1992 and 2006. Unconditional logistic regression analysis. Risk of postterm pregnancy (delivery at >or=42 weeks) and cesarean delivery following labor induction. Among 1,176,131 births, 8.94% were delivered postterm. Compared to normal weight women, the risk of postterm pregnancy in obese women was almost doubled (adjusted OR: 1.63, 95% CI 1.59-1.67). The risk of postterm pregnancy increased with increasing maternal age and was higher among primiparous women. The risk of cesarean section (CS) following labor induction postterm, increased with maternal age and BMI, and was more than doubled among women 35 years and older (adjusted OR 2.28, 95% CI 2.04-2.56). A fivefold risk of CS was seen among nulliparous women (adjusted OR 5.05, 95% CI 4.71-5.42). Parous women with a previous CS undergoing labor induction had a sevenfold increased risk of CS postterm (adjusted OR 7.19, 95% CI 5.93-8.71). Nulliparity, advanced maternal age and obesity were the strongest risk factors for postterm pregnancy and CS following labor induction in postterm pregnancy. Including maternal risk factors to the cervical assessment may improve prediction of vaginal delivery following labor induction in postterm pregnancy.
Article
To estimate the association of labor induction with the risk of a cesarean delivery for nulliparous women presenting at term at a regional hospital. This was a retrospective cohort study of cesarean delivery among nulliparous women delivering a live, singleton, vertex pregnancy at term. We used clinical data from electronic hospital obstetric records at a large, regional, obstetric hospital, approximating a population-based cohort. Multivariable logistic regression was used to explore risk factors associated with cesarean delivery, and the fraction of cesarean deliveries attributable to the use of labor induction was estimated. From a cohort of 24,679 women, 7,804 met inclusion criteria. Labor induction was used in 43.6% of cases, 39.9% of which were elective. Use of labor induction was associated with an increased odds of cesarean delivery (crude odds ratio 2.67, 2.40-2.96) and the association remained significant (adjusted odds ratio 1.93, 1.71-2.2) after adjustment for maternal demographic characteristics, medical risk, and pregnancy complications. The contribution of labor induction to cesarean delivery in this cohort was estimated to be approximately 20%. Labor induction is significantly associated with a cesarean delivery among nulliparous women at term for those with and without medical or obstetric complications. Reducing the use of elective labor induction may lead to decreased rates of cesarean delivery for a population. II.
Article
To determine whether changing the definition of the group to which induction is being compared (ie, noninduced delivering during the same week as those induced compared with two definitions of expectant management) changes the association of labor induction and increased cesarean risk. A New York State birth-certificate database was used to estimate odds ratios for cesarean delivery associated with labor induction at term. The analyses used three definitions of controls: cesarean delivery after induction compared with after spontaneous labor by week (week-to-week), induction at a given gestation age compared with expectant management of all other women after gestational age (all above), or induction at a given gestational age compared with expectant management of all other women at or after that gestational age (at or above). Chi-square logistic regression was used for comparisons and adjustment for possible confounders. All variations of comparison groups were associated with increased unadjusted cesarean risk after induction, although not after 39 weeks in the all-above group. After adjustment, increased risk persisted from 37 to 41 weeks using the week-to-week group and from 38 to 41 weeks in the at-or-above group (odds ratios 1.24 to 1.45) but was no longer significant in the all-above group. The excess cesarean delivery risk associated with labor induction is between 1 and 2 per 25 inductions. Labor induction is associated with increased cesarean risk whether using a week-to-week comparison group or an expectant group that includes women the same week or beyond that of the index induction, even after adjustment for parity, high-risk factors, and demographic variables. Although the magnitude of increased risk for a given woman undergoing induction is not large, women nonetheless should be informed of this increased risk. II.
Article
To determine whether preeclampsia is associated with an increased risk of cesarean delivery if labor is induced. This retrospective cohort study of 3505 women >or=24 weeks gestation with singleton pregnancies undergoing labor induction compares cesarean delivery rates between preeclamptics and non-preeclamptics. Multivariable logistic regression analysis was used to control for potential confounders including unfavorable cervix (Bishop score <or=5), method of labor induction, maternal age, parity, gestational age, race/ethnicity, epidural use, medical insurance, and marital status. Among term nulliparous women undergoing labor induction, preeclamptics had a higher cesarean delivery rate then non-preeclamptics (81/267, 30% vs. 363/1568, 23%; p = 0.011), as did preeclamptic compared with non-preeclamptic women who were term and multiparous (10/64, 16% vs. 55/900, 6%, p = 0.003). Preterm preeclamptics also had more cesarean deliveries compared with non-preeclamptics among nulliparous (48/164, 29% vs. 16/245, 7%; p < 0.001) and multiparous (13/72, 18% vs. 18/225, 8%; p = 0.015) women. In multivariable analysis, preeclampsia still conferred an increased risk of cesarean delivery if labor was induced (adjusted odd ratio = 1.90, 95% CI 1.45-2.48). Women with preeclampsia undergoing labor induction had higher cesarean delivery rates compared with non-preeclamptics regardless of parity or gestational age. However, the majority of women with preeclampsia still had successful vaginal deliveries.
Article
To identify risk factors for cesarean delivery in patients with an unfavorable cervix undergoing an indicated induction of labor. This is a secondary analysis of combined data from three prospective randomized trials comparing cervical ripening methods in singleton pregnancies with an unfavorable cervix seeking to identify risk factors for cesarean delivery. Nine hundred and five women underwent an induction of labor for a variety of indications. Gestational age ranged from 27.0-42.8 weeks (mean of 37.8 weeks) and initial Bishop's score from 0-6 (mean 2.5). There were 613 vaginal deliveries (67.7%) and 292 cesarean deliveries (32.2%). Factors associated with an increased risk for cesarean delivery included nulliparous status, Bishop's score <or=1, body mass index >40 and diabetes mellitus. Risk factors for cesarean delivery in women undergoing an indicated induction include a low Bishop's score, high BMI, nulliparity and diabetes.
Article
We sought to determine maternal factors that influence success of labor induction and whether the probability of cesarean delivery changed with time during induction. We performed a retrospective cohort study of 1650 singleton pregnancies induced at a gestation of 37 weeks or longer, with birthweights of 2500 g or greater, and without congenital anomalies. We used multivariate logistic regression to calculate odds ratios for cesarean. Nulliparity (odds ratio [OR] 7.8, 95% confidence interval [CI] 5.7 to 11), hypertension (OR 1.4, 95% CI 1.1 to 1.8), diabetes (OR 2.2, 95% CI 1.6 to 3.1), maternal age 28.8 years old or older (OR 1.3, 95% CI 1.2 to 1.4), and birthweight of 3441 g or greater (OR 1.6, 95% CI 1.2 to 2.0) were significantly associated with cesarean. Cesarean risk increased linearly with time by an average of 3.8% per 6 hours. Risk of cesarean increases over the duration of induction but does not reach clinical certainty. Cesarean probability is greater with nulliparity, hypertension, diabetes, older maternal age, or higher birthweight. Inductions without stated indications may not carry an increased risk of cesarean.
Article
The rates of perinatal mortality and neonatal morbidity are higher for post-term pregnancies than for term pregnancies. It is not known, however, whether the induction of labor results in better outcomes than does serial fetal monitoring while awaiting spontaneous labor. We studied 3407 women with uncomplicated pregnancies of 41 or more weeks' duration. The women were randomly assigned to undergo induction of labor or to have serial antenatal monitoring and spontaneous labor unless there was evidence of fetal or maternal compromise, in which case labor was induced or cesarean section was performed. In the induction group, labor was induced by the intracervical application of prostaglandin E2. Serial antenatal monitoring consisted of counts of fetal kicks, nonstress tests, and assessments of amniotic-fluid volume. The outcomes we measured were the rates of perinatal mortality, neonatal morbidity, and delivery by cesarean section. Among the 1701 women in the induction group, 360 (21.2 percent) underwent cesarean section, as compared with 418 (24.5 percent) of the 1706 women in the monitoring group (P = 0.03). This difference resulted from a lower rate of cesarean section performed because of fetal distress among the women in the induction group (5.7 percent vs. 8.3 percent, P = 0.003). When two infants with lethal congenital anomalies were excluded, there were no perinatal deaths in the induction group and two stillbirths in the monitoring group (P not significant). The frequency of neonatal morbidity was similar in the two groups. In post-term pregnancy, the induction of labor results in a lower rate of cesarean section than serial antenatal monitoring; the rates of perinatal mortality and neonatal morbidity are similar with the two approaches to management.
Article
The goal of this project was to study the increasing risk of induction of labor in a community hospital and to determine whether it had an adverse effect on the rate of cesarean delivery. Study Design: From January 1, 1990, through July 31, 1997, 18,055 consecutive singleton pregnancies in women who were candidates for labor were reviewed via a comprehensive perinatal database. The risk of and indication for induction were reviewed. Cesarean delivery rates were calculated for nulliparous and multiparous patients by indication for induction and were compared with rates for patients who had spontaneous labor. Overall trends in cesarean delivery were reviewed for the duration of the study period. The annual induction rate significantly rose from 32% to 43% at the conclusion of the study period. Labor was induced in nearly 40% of nulliparous patients. Postdate pregnancy was the most common indication for induction, although few patients were at or beyond 42 weeks' gestation. The cesarean delivery rate remained at or below 20% for the years of the study. No increase was noted in spite of the increasing risk of induction. However, for nulliparous patients who had elective induction of labor, the risk of cesarean delivery was twice that of nulliparous patients who had spontaneous labor. The use of induction methods has significantly increased in this community hospital. More than 40% of patients are now candidates for induction. The cesarean delivery rate remains low in this facility in spite of a marked increase in risk of operative delivery for nulliparous patients who undergo induction.
Article
To quantify the risk of cesarean delivery associated with elective induction of labor in nulliparous women at term. We performed a cohort study on a major urban obstetric service that serves predominantly private obstetric practices. All term, nulliparous women with vertex, singleton gestations who labored during an 8-month period (n = 1561) were divided into three groups: spontaneous labor, elective induction, and medical induction. The risk of cesarean delivery in the induction groups was determined using stepwise logistic regression to control for potential confounding factors. Women experiencing spontaneous labor had a 7.8% cesarean delivery rate, whereas women undergoing elective labor induction had a 17.5% cesarean delivery rate (adjusted odds ratio [OR] 1.89; 95% confidence interval [CI] 1.12, 3.18) and women undergoing medically indicated labor induction had a 17.7% cesarean delivery rate (OR 1.69; 95% CI 1.13, 2.54). Other variables that remained significant risk factors for cesarean delivery in the model included: epidural placement at less than 4 cm dilatation (OR 4.66; 95% CI 2.25, 9.66), epidural placement after 4 cm dilatation (OR 2.18; 95% CI 1.06, 4.48), chorioamnionitis (OR 4.61; 95% CI 2.89, 7.35), birth weight greater than 4000 g (OR 2.59; 95% CI 1.69, 3.97), maternal body mass index greater than 26 kg/m2 (OR 2.36; 95% CI 1.61, 3.47), Asian race (OR 2.35; 95% CI 1.04, 5.34), and magnesium sulfate use (OR 2.18; 95% CI 1.04, 4.55). Elective induction of labor is associated with a significantly increased risk of cesarean delivery in nulliparous women. Avoiding labor induction in settings of unproved benefit may aid efforts to reduce the primary cesarean delivery rate.
Article
To determine the effects of elective induction on the risk of cesarean delivery in a cohort of women with low-risk term pregnancies and to evaluate the costs of elective induction services within our hospital system. Records of 1135 eligible women with low-risk, singleton, vertex pregnancies at 38-41 weeks' gestation who were eligible for vaginal delivery were analyzed retrospectively after elective induction (n = 263) or spontaneous labor (n = 872). Outcome measures included cesarean delivery and direct costs. Variables evaluated were parity, maternal age, estimated gestational age, birth weight, prior cesarean delivery, epidural anesthetic use, and provider category. Analysis was by univariable and multivariable regression modeling. Elective induction placed nulliparas at a twofold higher risk for cesarean delivery (odds ratio 2.4, 95% confidence interval 1.2, 4.9) after adjustment for birth weight, maternal age, and gestational age. We found a significantly increased risk of cesarean delivery with increased birth weight for nulliparas (2-66.7%). Increasing maternal age increased the risk of cesarean delivery in all parity groups (P <.05), but particularly among nulliparas (3-26.3%) (P <.001). Electively induced labors that ended in vaginal delivery cost $273 more and required an average of 4 hours more in the hospital before delivery than did noninduced vaginal deliveries (P <.001). Elective induction significantly increased the risk of cesarean delivery for nulliparas, and increased in-hospital predelivery time and costs.
Article
This study was undertaken to examine associations between induction of labor and maternal and neonatal outcomes among women without an identified indication for induction. This was a population-based cohort study of 2886 women with induced labor and 9648 women with spontaneous labor who were delivered at 37 to 41 weeks' gestation, all without identified medical and obstetric indications for induction. Among nulliparous women 19% of women with induced labor versus 10% of those with spontaneous labor underwent cesarean delivery (adjusted relative risk, 1.77; 95% confidence interval, 1.50-2.08). No association was seen in multiparous women (relative risk, 1.07; 95% confidence interval, 0. 81-1.39). Among all women induction was associated with modest increases in instrumental delivery (19% vs 15%; relative risk, 1.20; 95% confidence interval, 1.09-1.32) and shoulder dystocia (3.0% vs 1. 7%; relative risk, 1.32; 95% confidence interval, 1.02-1.69). Among women who lacked an identified indication for induction of labor, induction was associated with increased likelihood of cesarean delivery for nulliparous but not multiparous women and with modest increases in the risk of instrumental delivery and shoulder dystocia for all women.
Article
To determine whether elective induction of labor in nulliparous women is associated with changes in fetomaternal outcome when compared with labor of spontaneous onset. Study Design: All 80 labor wards in Flanders (Northern Belgium) comprised a matched cohort study. From 1996 through 1997, 7683 women with elective induced labor and 7683 women with spontaneous labor were selected according to the following criteria: nulliparity, singleton pregnancy, cephalic presentation, gestational age at the time of delivery of 266 to 287 days, and birth weight between 3000 and 4000 g. Each woman with induced labor and the corresponding woman with spontaneous labor came from the same labor ward, and they had babies of the same sex. Both groups were compared with respect to the incidence of cesarean delivery or instrument delivery and the incidence of transfer to the neonatal ward. Cesarean delivery (9.9% vs 6.5%), instrumental delivery (31.6% vs 29.1%), epidural analgesia (80% vs 58%), and transfer of the baby to the neonatal ward (10.7% vs 9.4%) were significantly more common (P <.01) when labor was induced electively. The difference in cesarean delivery was due to significantly more first-stage dystocia in the induced group. The difference in neonatal admission could be attributed to a higher admission rate for maternal convenience when the women had a cesarean delivery. When compared with labor of spontaneous onset, elective labor induction in nulliparous women is associated with significantly more operative deliveries. Nulliparous women should be informed about this before they submit to elective induction.
Article
To determine whether the medical initiation of labor places the multiparous woman at increased risk of cesarean section. This study was a retrospective, case-control assessment of the risk of cesarean section in multiparas with no medical or obstetric complications and vertex presentations whose induction of labor at term was judged to be elective by chart analysis. Case women were matched for age, parity, gestational age and staff obstetrician with controls in spontaneous labor, and the rates of cesarean delivery were compared. Three hundred four case-control pairs were studied. No significant difference was observed in the rate of cesarean delivery between the two groups. The rate of cesarean section in the electively induced group was 3.6% versus 4.3% in the control group (P = .6670). Neither cervical state nor use of cervical ripening agents significantly affected the rate of cesarean delivery. As compared with spontaneous labor, the elective induction of labor in multiparous women without complications does not predispose to cesarean delivery.
Article
The purpose of this study was to evaluate the effect of induction on the route of delivery in nulliparous women laboring at term in a community hospital system. From April 1997 to October 1999, there were 7282 deliveries in nulliparous patients who met inclusion criteria. Cesarean delivery rates were calculated for patients in spontaneous labor and for patients who underwent induction. Among 4635 women (63.7%) in spontaneous labor, the cesarean delivery rate was 11.5% versus 23.7% among the 2647 (36.3%) patients who underwent induction. An important variable that affected the delivery route was the Bishop score at the initiation of the induction. The cesarean delivery rate was 31.5% among patients whose Bishop score was <5 at induction versus 18.1% for patients with a score > or =5(P <.001). The induction of labor in nulliparous patients, especially those women with an unfavorable cervix as measured by Bishop score, is associated with a significantly increased risk of cesarean delivery.
Article
To quantify the impact of labor induction and maternal age on cesarean delivery rates in nulliparous and multiparous women between 36 and 42 weeks' gestation. We performed a retrospective cohort study on 14,409 women delivering at two teaching hospitals in metropolitan Boston during 1998 and 1999. Women who had contraindications to labor, including a prior cesarean delivery, were excluded. The risks for cesarean delivery by induction status, gestational age by completed week between 36 and 42 weeks, maternal age <35, 35-39, and >/=40 years, and stratified by parity, were calculated by logistic regression. In nulliparas, labor induction was associated with an increase in cesarean delivery from 13.7% to 24.7% (adjusted odds ratio [OR] 1.70; 95% confidence interval [CI] 1.48, 1.95]). In multiparas, induction was associated with an increase from 2.4% to 4.5% (OR 1.49; 95% CI 1.10, 2.00). Other variables that placed a nulliparous woman at increased risk for cesarean delivery included maternal age of at least 35 years and gestational ages over 40 weeks. For multiparas, only maternal age 40 years or older and gestational age of 41 weeks were associated with an increase in cesarean deliveries. Induction of labor, older maternal age, and gestational age over 40 weeks each independently increase the risk for cesarean delivery in both nulliparous and multiparous women. Although the relative risk from induction is similar in nulliparas and multiparas, the absolute magnitude of the increase is much greater in nulliparas (11% versus 2.1%).
Article
The purpose of this study was to assess the contribution of the individual physician to the probability of cesarean delivery among nulliparous women who undergo elective induction. A cohort study compared spontaneous labor and elective induction for all term, singleton, and cephalic nulliparous gestations over 2 years (1999-2000) at a large metropolitan hospital (n = 3215). Bivariate analysis was used to identify significant variables that were related to cesarean delivery. Logistic regression analysis was used to calculate the adjusted risk of cesarean delivery and to assess the independent effect of individual physician practice on cesarean delivery. Physician effect was evaluated in terms of its relative contribution to the explanatory power of the logistic regression model to predict cesarean delivery. The adjusted odds ratio for cesarean delivery with elective induction was 1.78 (95% CI, 1.39, 2.27). Using forward stepwise regression, the individual physician was a significant independent risk factor in the model with an R square statistic increase from 0.194 to 0.249 when the physician statistic was added to the final model. Nulliparous women are at a significant increased risk of cesarean delivery if elective induction is performed. The individual physician has a contributing effect to this increased risk.
Article
The objective of the study was to estimate the validity of obstetric procedures and diagnoses in California patient discharge data. We randomly sampled 1611 deliveries from 52 of 267 California hospitals that performed more than 678 eligible deliveries in 1992 to 1993. We compared hospital-reported procedures and diagnoses against our recoding of the same records. Cesarean, forceps, and vacuum delivery were accurately reported, with sensitivities and positive predictive values exceeding 90%. Episiotomy was underreported (70% sensitivity). Cesarean indications were reported with at least 60% sensitivity, except uterine inertia, herpes, and long labor. Among comorbidities, sensitivity exceeded 60% for chorioamnionitis, diabetes, premature labor, preeclampsia, and intrauterine death. Sensitivity was poor (less than 60%) for anemia, asthma, thyroid disorders, mental disorders, drug abuse, genitourinary infections, obesity, fibroids, excessive fetal growth, hypertension, premature rupture, polyhydramnios, and postdates. The validity of hospital-reported obstetric procedures and diagnoses varies, with moderate to high accuracy for some codes but poor accuracy for others.
Article
Studies of cesarean delivery (CD) rates among women undergoing induction of labor (IOL) often compare such women to women experiencing spontaneous labor at similar gestational ages. We sought to examine the association between IOL at various gestational ages and CD, accounting for the effect of increased gestational age among the comparison group who were managed expectantly. We conducted a retrospective cohort study of all term, singleton, cephalic presentation pregnancies delivered at our institution over 15 years excluding cesarean deliveries before labor. For each gestational age of induction, we created a comparison group of women who were undelivered at that gestational age, and who experienced labor at some future gestational age. In women undergoing IOL at 38 weeks gestation, the CD rate was 11.9% as compared to 13.3% (P = .42) of women beyond 38 weeks gestation. The CD rate for induction of labor compared to ongoing pregnancy was 14.3% versus 15.0% (P = .62) at 39 weeks, 20.4% versus 19.0% (P = .41) at 40 weeks, and 24.3% versus 26.0% (P = .39) at 41 weeks. When controlling for potential confounding, there was a higher rate of CD among women with expectant management beyond 38 weeks (adjusted odds ratio [AOR] 1.80; 95% CI 1.29-2.53), 39 weeks (1.39; 95% CI 1.08-1.80), and 40 weeks (AOR 1.27; 95% CI 1.00-1.62). Our findings suggest that IOL may not increase a woman's risk of CD when compared to expectant management. While this question has been addressed prospectively at 41 weeks gestation, it requires further examination at earlier gestations and among various subgroups.
Article
To develop a methodology to identify indications and normative rates for elective primary cesarean delivery using administrative data. All delivery discharges in 1995, as reported to the California Office of Statewide Health Planning and Development (secondary data). Retrospective population based study. Data were entered into a recursive partitioning algorithm to develop a hierarchy of conditions by which patients with multiple conditions could be sorted with respect to the binary outcome of labor or elective primary cesarean without labor. This hierarchy was examined for its clinical consistency, validated on a second sample, and compared with results obtained from logistic regression. Four percent (19,664) of delivery discharges in 1995 underwent elective primary cesarean. Twelve clinical conditions contributed to the hierarchy, and accounted for 92.9 percent of all women experiencing elective primary cesarean delivery. The remaining 7.1 percent of the elective primary cesarean cases were classified as "unspecified." A standardized methodology (utilizing recursive partitioning algorithms) for assigning indications for elective primary cesarean is presented. This methodology relies on administrative data, classifies women with complex comorbidity patterns into clinically relevant subpopulations, and can be used to establish normative rates for benchmarking specific indications for cesarean delivery.
Article
Estimate the frequency of failure to follow the French consensus guidelines for elective induction, and assess how failure affects the rate of cesarean delivery. We compared cesarean rates according to mode of onset of labor among 5,046 low-risk patients. Violation of the guidelines was defined as induction before 38 weeks or with a Bishop score <5 or with prostaglandins. The cesarean risk was analysed with a bivariable and then a multivariable analysis, which used a multilevel logistic model. Women with electively induced and spontaneous labor had identical cesarean rates (4.1%). The guidelines were not followed in 23.2% of elective inductions. The risk of cesarean was higher after induction with a Bishop score <5, than after spontaneous labor (adjusted OR=4.1, 95% CI [1.3-12.9]), while elective induction with a favourable cervix did not increase the cesarean risk. In nulliparas, failure to follow the guidelines tripled the risk of cesarean (adjusted OR=3.2 [1.0-10.2]). On the other hand, elective induction of labor for women with a favourable cervix did not increase the risk of cesarean over the risk with spontaneous labor. Elective induction does not appear to increase the cesarean rate when the guidelines are met. Electively inducing labor with a low Bishop score increased the risk of cesarean, especially in nulliparas.