Here is a new study that suggests that it may be better to await spontaneous labor in first-time obese mothers with an unripe cervix, rather than trying to force labor to start regardless of the Bishop's Score.
Am J Obstet Gynecol. 2014 Jan 31. pii: S0002-9378(14)00063-5. doi: 10.1016/j.ajog.2014.01.034. [Epub ahead of print] Risk of cesarean in obese nulliparous women with unfavorable cervix: elective induction vs expectant management at term. Wolfe H1, Timofeev J2, Tefera E3, Desale S3, Driggers RW2. PMID: 24486226
OBJECTIVE: The objective of the study was to examine maternal and neonatal outcomes in obese nulliparous women with an unfavorable cervix undergoing elective induction of labor compared with expectant management after 39.0 weeks. STUDY DESIGN: This was a retrospective analysis of a cohort of nulliparous women with a vertex singleton gestation who delivered at MedStar Washington Hospital Center from 2007 to 2012. Patients with unfavorable cervix between 38.0 and 38.9 weeks (modified Bishop <5) and a body mass index of 30.0 kg/m2 or greater at the time of delivery were included. Women undergoing elective induction between 39.0 and 40.9 weeks' gestation were compared with those who were expectantly managed beyond 39.0 weeks. Outcomes were analyzed using χ2, Student t, or Wilcoxon rank sum tests as appropriate with a significance set at P < .05. RESULTS: Sixty patients meeting inclusion criteria underwent elective induction of labor and were compared with 410 patients expectantly managed beyond 39.0 weeks. The rate of cesarean delivery was significantly higher in the electively induced group (40.0% vs 25.9%, respectively, P = .022). Other maternal outcomes, including operative vaginal delivery, rate of third- or fourth-degree lacerations, chorioamnionitis, postpartum hemorrhage, and a need for a blood transfusion were similar. The neonatal intensive care unit admission rate was higher in the electively induced group (18.3% vs 6.3%, P = .001). Birthweight, umbilical artery pH less than 7.0, and Apgar less than 7 at 5 minutes were similar. CONCLUSION: Elective labor induction at term in obese nulliparous parturients carries an increased risk of cesarean delivery and higher neonatal intensive care unit admission rate as compared with expectant management.