Elective cervical ripening in women beyond the 290th day of pregnancy: a randomized trial comparing 2 dinoprostone preparations.

Objective: To determine the better performer among cervical ripening agents for the elective induction of labor.

Study Design: An open-label, randomized study was done in consecutive patients undergoing elective induction of labor at the 41st week and beyond. Inclusion criteria were: singleton pregnancy, gestational age ascertained through first-trimester ultrasound, Bishop score <4 and nulliparity. Exclusion criteria were: oligohydramnios, maternal/fetal disorder or pregnancy complication, previous uterine surgery, rupture of membranes and presence of uterine activity. Patients received either slow-release dinoprostone vaginal insert (VI) or 0.5-mg dinoprostone intracervical (IC) gel, twice, 6 hours apart.

Results: Women receiving VI showed increased risk of entering labor without further stimulation (OR = 6.48, 95% CI 2.06-21.67, p < 0.001) and delivering vaginally within 24 hours (OR = 2.71, 95% CI 1.19-6.21, p = 0.01) in comparison to those receiving IC gel. A stay in the hospital (> 4 days) was more prevalent in women treated with IC gel in comparison to those treated with VI (OR = 2.35, 95% CI 1.04-5.37).

Conclusion: Preinduction cervical ripening with the dinoprostone slow-release vaginal insert is associated with a hight rate of women undergoing vaginal delivery within 24 hours, with a shorter stay. Considering its good performance, the dinoprostone slow-release vaginal insert is the first choice for elective induction of labor in postdate pregnancy.