C/S more likely with expectant management than with induction

September 15, 2009

Women who undergo elective induction of labor at 41 weeks or more of gestation have a decreased risk for cesarean delivery and meconium-stained amniotic fluid compared to those who undergo expectant management of pregnancy, according to a study in the Aug. 18 Annals of Internal Medicine.

Women who undergo elective induction of labor at 41 weeks or more of gestation have a decreased risk for cesarean delivery and meconium-stained amniotic fluid compared to those who undergo expectant management of pregnancy, according to a study in the Aug. 18 Annals of Internal Medicine.

Aaron B. Caughey, MD, of the University of California in San Francisco, and colleagues conducted a systematic review of 36 studies, including 11 randomized controlled trials (RCTs) and 25 observational studies that reported outcomes associated with elective induction or expectant management at or after 37 weeks and before 42 weeks of gestation.
In nine RCTs, the researchers found that expectant management was associated with a higher risk of cesarean section than elective induction, particularly in women at or beyond 41 completed weeks of gestation (OR, 1.21). However, they did not observe a statistically significant group difference in women who had fewer than 41 completed weeks of gestation. They also found that expectant management was associated with a higher risk of meconium-stained amniotic fluid (OR, 2.04).

“In my opinion, the principal service provided by Caughey and colleagues’ systematic review is to spur obstetricians to rethink the closely held dogma that elective induction of labor increases the rate of cesarean births," states the author of an accompanying editorial. “We need well-designed randomized controlled trials of induction versus expectant management at 39 to 41 weeks that are sufficiently powered to assess critical subgroups, such as parity, cervical examination at randomization, and others."

Caughey AB, Sundaram V, Kaimal AJ, et al. Systematic review: elective induction of labor versus expectant management of pregnancy. Ann Intern Med. 2009;151:252-263.