Primary cesarean section in term, low-risk multiparous women: a single clinic retrospective observational study

Background: Multiparous women who have previously delivered vaginally are generally considered to be at low risk for cesarean section. We aimed to determine the incidence rate and indications for primary cesarean section and operative vaginal deliveries among multiparous women with previous vaginal births. Patients and methods: Multiparous women who had delivered their babies in our clinic between January 2004 and December 2019 were enrolled in this retrospective observational study. The inclusion criteria were as follows: delivery at 37 weeks of gestation or more, singleton pregnancy with a live fetus, had one or more past vaginal deliveries including instrumental vaginal birth, and no history of previous cesarean section. Women with placenta previa, abruptio placentae, severe pregnancy-induced hypertension, and uncontrolled medical diseases were referred to tertiary hospitals and excluded from this study. The frequency of occurrence and indications for cesarean section and vacuum extraction, duration of labor, and the effect of induction of labor on the cesarean section rates were analyzed. Results: A total of 3094 multiparous women were enrolled. Primary cesarean section was performed in 30 women (30/3094=0.97%). The indications for cesarean section included the following: breech presentation in 28 women, myomectomy after the first vaginal birth in one (of 29 elective cesarean sections), and failed vacuum extraction after a prolonged second stage in one (one emergency cesarean section). Vacuum extraction was performed in 61 women (61/3094=2.0%), the indications for which were non-reassuring fetal status (n=38), prolonged 2nd stage of labor (n=10), and narrow pelvic outlet (n=10). Vaginal breech delivery occurred in 11 women. Induction of labor (n=402) did not affect the cesarean section rate. Conclusion: In multiparous women, breech presentation was the main indication for primary cesarean sections, and the cesarean section rate was very low in women with cephalic presentation.