Vaginal delivery rate in post-term pregnancies with one versus more than one dinoprostone gel administrations: an observational study.

AIM: The study aims to calculate the probability of a successful vaginal delivery in post-term low-risk women by using a set of predictors (maternal, fetal, and ultrasonographic) according to the number of dinoprostone gel applications. METHODS: This was an observational study of a cohort of 174 low-risk post-term singleton pregnancies. Parity, cervical status and length, and amniotic fluid volume (AFI) were evaluated immediately before prostaglandin gel induction at the Department of Obstetrics and Gynecology, University of Bologna, Bologna, Italy between January 2010 and October 2011. RESULTS: A consistent difference in vaginal delivery rates was observed for women who had one gel administration (Group 1) versus those who received either two or three gel administrations (Group 2): 77.5% at 24 hours and 97.4% at 48 hours vs. 27% at 24 hours and 54% at 48 hours (P <0.001 for both the comparisons) respectively. The predictors of a vaginal delivery were cervix dilatation and short cervix for Group 1, lower AFI for Group 2, and parity for both groups. CONCLUSION: Women who require more than one gel administration have a lower rate of vaginal delivery at 24 and 48 hours. Maternal, fetal, and ultrasonographic parameters can predict a successful vaginal delivery.