(HealthDay)—For healthy nulliparous women with a Bishop score of 5 or less, elective induction did not significantly impact the rate of cesarean delivery compared with expectant management, according to a study published online Nov. 5 in Obstetrics & Gynecology.

Nathaniel R. Miller, M.D., from the Carl R. Darnall Army Medical Center in Fort Hood, Texas, and colleagues conducted a randomized controlled trial involving nulliparous women aged 18 years or older with a singleton gestation and a Bishop score of 5 or less. Participants were randomly allocated to undergo elective induction of (within one week of enrollment but not before 39 0/7 weeks of gestation; 82 ) or expectant management (80 patients). One hundred sixty-two patients were enrolled, assuming a 20 percent rate in the control group, 80 percent power, and a goal to detect a two-fold increase in the induction of labor group.

The researchers found that the cesarean delivery rates were 30.5 and 17.7 percent in the induction of labor and expectant management groups, respectively (relative risk, 1.72; 95 percent confidence interval, 0.96 to 3.06).

"In summary, in this randomized controlled trial of healthy nulliparous women at 39 0/7 weeks of estimated gestation with an unfavorable cervix, of labor did not double the cesarean delivery rate," the authors write.