Risks of induction of labour in uncomplicated term pregnancies

Our objective was to evaluate the risks of maternal and perinatal morbidity associated with induction of labour in uncomplicated term pregnancies. We conducted a retrospective cohort study including 7430 women, not referred f rom another institution, with a single baby in vertex presentation, and del ivering between 38 and 40 weeks of pregnancy. Among these women, 3546 were excluded for prelabour pregnancy complications. Relative risks (RR), adjust ed for parity, were computed to compare 3353 women who went into labour spo ntaneously with 531 women whose labour was induced. Induction of labour was found to be associated with a higher risk of caesarean section [RR = 2.4, 95% CI 1.8, 3.4]. Use of non-epidural [RR = 1.5, 95% CI 1.2, 1.8] and of ep idural analgesia [RR = 1.4, 95% CI 1.1, 1.7] was more frequent after labour induction. Resuscitation [RR = 1.2, 95% CI 1.0, 1.5], admission to the int ensive care unit [RR = 1.6, 95% CI 1.0, 2.4] and phototherapy [RR = 1.3, 95 % CI 1.0, 1.6] were more frequent after induction of labour. Results were s imilar when controlling simultaneously for parity, maternal age, gestationa l age, year of delivery, birthweight and the physician in charge of deliver y in a logistic regression analysis. The results of this study suggests tha t induction of labour is associated with a higher risk of caesarean section and of some perinatal adverse outcomes. Induction of labour should be rese rved for cases where maternal and perinatal benefits outweigh the risk of t hese complications.