Risk of Cesarean Section Delivery after Induction of Labor at Postterm Pregnancy in Nulliparous Women

Chi, Kyung Suk; Kim, Jun Su; Jang, Eun Jeong; Sim, Jae Chul; Yang, Hoi Saeng; Lee, Hyung Jong; Ha, Jun Young; Hwang, Young; Kim, Do Gyun

Abstract

OBJECTIVE: The purpose of this study was to evaluate the risk of cesarean section in nulliparous women who undergone induction at postterm pregnancy. METHODS: The retrospective study was conducted from March, 1997 to March, 2005 by reviewing 331 nulliparous patients more than 41 weeks' gestation delivered after induction at our Hospital. The evaluated variables to assess the risk of cesarean section were maternal age, body mass index (BMI), gestational age (GA), Bishop scores (BS), fetal body weight (FBW), fetal head circumference (FHC) and fetal sex. t-test and x2-test were used to compare these categorical variables. RESULTS: The study included 331 nulliparous singleton pregnant women undergoing elective induction for postterm pregnancy: 127 (38.4%) delivered babies by cesarean section due to induction failure, progression failure and fetal distress, whereas 204 (61.6%) delivered vaginally. The mean maternal ages were 27.59+/-2.57 in cesarean delivery group and 26.99+/-2.61 in vaginal delivery group. The average values of BMI at postterm in cesarean and vaginal delivery groups were 26.70+/-2.82 and 25.75+/-2.67 kg/m2. GA was 41.36+/-0.27 weeks in cesarean delivery group, whereas 41.20+/-0.19 weeks in vaginal delivery group. The average FBW and FHC were 3460.31+/-358.22 g and 34.59+/-1.18 cm in cesarean delivery group, compared to 3363.95+/-361.22 g and 34.03+/-1.34 cm in vaginal delivery group. CONCLUSION: The BMI, FBW and FHC have linked to the risk of cesarean delivery in nulliparous women who underwent elective induction. Thus, these information would provide the useful tools to assess the risk of cesarean section in postterm nulliparous patients for planning an induction.