To evaluate the effectiveness of a second cervical ripening procedure in primiparous women with an unfavourable persistent cervix.

This retrospective, before-and-after, comparative study was conducted at Rouen University Hospital, France between January 1st, 2018, and August 15th, 2022. Inclusion criteria were women with indications for labour induction with singleton term pregnancies in cephalic presentation and with a Bishop score <6 who required an initial cervical ripening. All women underwent an initial cervical ripening procedure with either a balloon catheter or vaginal dinoprostone. In the before-protocol group, labour induction was mostly pursued with oxytocin regardless of cervical status. In the after-protocol group (post-November 2020), a second cervical ripening procedure was proposed if the Bishop score remained ≤ 4. The primary outcome was caesarean section rate. A sensitivity analysis was also performed in women with a Bishop score <6 after the first ripening.

A total of 384 women were included in the study and were then divided in the before- protocol group (n=184) or in the after-protocol group (n=200). The caesarean section rate significantly decreased in the after-protocol group (31% vs. 40.8%; p=0.04). Bishop scores before oxytocin administration were significantly higher in the after-protocol group (median: 6 vs. 5; p=0.01). After adjustment, no significant association was found between the use of the new protocol and the caesarean section risk (OR 0.82; 95% CI [0.58–1.34]). Factors independently associated with caesarean delivery were advanced maternal age, women not born in France, and lower Bishop scores both before and after cervical ripening. In the subgroup of women with persistent unfavourable cervix, the second procedure improved Bishop scores but was not associated with a significant reduction in caesarean section rate.

A second cervical ripening procedure for women with persistent low Bishop scores was not significantly associated with reduced caesarean section rates. Further studies are needed to evaluate whether combining cervical ripening methods can enhance vaginal delivery rates.