Induction of labour at or beyond 37 weeks' gestation

• Published in: Cochrane database of systematic reviews 2020-07, Vol.7 (7), p.CD004945-CD004945
• Main Authors: Middleton, Philippa, Shepherd, Emily, Morris, Jonathan, Crowther, Caroline A, Gomersall, Judith C
• Format: Article
• Language: English
• Subjects: Cesarean Section - statistics & numerical data; Female; Gestational Age; Humans; Induction of labour; Infant; Infant Mortality; Infant, Newborn; Intensive Care Units, Neonatal - statistics & numerical data; Labor, Induced - adverse effects; Perinatal Death; Pregnancy; Pregnancy & childbirth; Pregnancy, Prolonged; Randomized Controlled Trials as Topic; Risk; Stillbirth - epidemiology; Watchful Waiting
• ISSN: 1469-493X
• DOI: 10.1002/14651858.CD004945.pub5

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. 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. 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. 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. 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. 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