Induction of Labour in Low-Risk Pregnancies before 40 Weeks of Gestation: A Systematic Review and Meta-Analysis [11P]

Abstract

INTRODUCTION: Retrospective data suggest that adverse outcomes in low-risk pregnancies are lowest at 39 weeks, and systematic reviews of randomized controlled trials (RCTs) suggests that induction of labour (IOL) after 37 weeks regardless of indication and cervical favourability is associated with lower rates of caesarean deliveries (CD) when compared with expectant management. Our objective was to determine whether IOL <40 weeks reduces CD rates and improves pregnancy outcomes. METHODS: We conducted a systematic review of RCTs comparing IOL to expectant management in low-risk women. We searched four databases until November 2016 using appropriate keywords and MeSH terms. Two authors independently completed title screening, data extraction and risk-of-bias (ROB) assessment using the Cochrane ROB tool. Meta-analysis was performed using RevMan 5.3 and results were reported as odds ratios and 95% confidence intervals (OR, 95%CI). RESULTS: We identified 2523 titles and included 14 eligible articles, most of which had low ROB. Outcomes for IOL (n=1268) vs. expectant management (n=1266) were as follows: CD 1.02 (0.81, 1.28), operative vaginal delivery 1.32 (1.06, 1.66), infective morbidity 1.26 (0.79, 1.99), perinatal mortality 0.72 (0.14, 3.71), postpartum 1.00 (0.73, 1.38), neonatal admissions 0.71 (0.33, 1.51), abnormal cord gases 0.69 (0.26, 1.87) and low 5-minute Apgar scores 0.94 (0.44, 2.03). CONCLUSION: There were no differences in rates of CD or other adverse pregnancy outcomes when IOL <40 weeks is compared with expectant management in low-risk pregnancies. A policy of IOL at 39 weeks to lower CD rates and improve pregnancy outcomes can only be recommended under the confines of RCTs.