Post-term induction of labor revisited

Abstract

Post-term pregnancy (longer than 42 weeks or 294 days) occurs in approximately 10% of all singleton gestations. The adverse outcomes of post-term pregnancy include a substantial increase in perinatal mortality and morbidity. ACOG currently recommends induction of labor for low-risk pregnancy during the 43rd week of gestation. However, that recommendation dates from 1989. Recent reports mandate reconsideration of the management of post-term pregnancy, including reinterpretation of the statistical risk of stillbirth in post-term pregnancies using ongoing (undelivered) rather than delivered pregnancies as the denominator, which shows a far higher risk to post-term fetuses than believed. Recent data also suggest that the risk of cesarean delivery after induction of labor at term is lower than reported, possibly because of improvements in methods for cervical ripening. Those findings provide rationale for earlier labor induction in low-risk pregnancies.