[Induction of labour with oral misoprostol versus vaginal misoprostol: A before-after study]

The rate of induction of labor represented 22 % of deliveries in 2016 in France. Oral misoprostol (Angusta®) was marketed in France in the last quarter of 2018. The objective of our study was to compare the efficacy and safety of induction of labor with oral misoprostol compared to vaginal misoprostol in women with an unripe cervix.

We carried out a retrospective study before and after the implementation of oral misoprostol including all women with an unripe cervix who benefited from an induction of labor with a viable infant in vertex presentation, without uterine scar. During the first two-year period, women received 50μg of misoprostol in the posterior fornix, repeated 6hours later if needed. If labor had not started after 24hours, women received another dose of 50μg, which was repeated every 4hours until labor was established, up to a total dose of 150μg. During the second two-year period, women received two tablets of oral misoprostol 25μg every four hours if necessary, up to a total dose of 200μg. The primary endpoints were mode of delivery and neonatal safety.

During the two study periods, 1199 women received vaginal misoprostol and 1199 women received oral misoprostol including. The cesarean delivery rate was 21.8% during the first period and 21,3% during the second period (P=0.83). A 5-minutes Apgar score<7 was observed in 23 (1.9%) and 14 (1.2%) newborns in the vaginal misoprostol and oral misoprostol groups (P=0.14), respectively. An arterial cord pH<7.00 was observed in 6 (0.5%) and 7 (0.6%) newborns (P=0.99), respectively.

Oral misoprostol administered at the dose of 50μg every 4hours (up to a total dose of 200μg) is as effective and safe as the vaginal misoprostol to induce labor in women with an unripe cervix.