Induction of Labour: Post-term Pregnancy and Term Prelabour Rupture of the Membranes—Evidence for Practice

Abstract

Post-term pregnancy and prelabour rupture of the membranes at term are two common clinical problems in obstetric practice. Appropriate management of these situations has been controversial, and has centred on the choice between induction of labour, its timing and method, and expectant management. We now have the benefit of results from two large randomized trials, one involving only Canadian centres (post-term pregnancy), and the other trial, coordinated in Canada and involving centres in Canada and five other countries (term prelabour rupture of the membranes) which should help guide practice in these two important areas. The Post-term Trial results showed that a policy of induction was associated with a lower Caesarean section rate than a policy of expectant management, with no differences in perinatal mortality or morbidity. When the results of this trial are combined with all other trials in a meta-analysis, a policy of induction is associated with a significant reduction in perinatal mortality. The recently completed international trial on prelabour rupture of the membranes (Term PROM) showed no differences in serious neonatal infection or Caesarean section rates between a policy of induction of labour and expectant management, but maternal infection was reduced in the induction/oxytocin arm of the trial, and women viewed a policy of induction more positively than expectant management.