[Obstetrical prognosis of labour induction with mifepristone after 41 weeks of gestation]. / Pronostic obstétrical du déclenchement artificiel du travail au-delà de 41 semaines d'aménorrhée en fonction de la réponse à la mifépristone.

OBJECTIVE: To compare the mode of delivery in two groups of patients selected by their response after induction of labour with mifepristone. PATIENTS AND METHODS: We studied retrospectively 89 cases of labour induction with viable children after 41 weeks of gestation. Bishop scores were less than 6. Patients were given 200 mg of mifepristone per day for 48 h. They were retrospectively divided into group 1 (spontaneous onset of labour or premature rupture of membranes before the third day) and group 2 (not in labour by that date). RESULTS: The mean Bishop score at inclusion was 3.1 +/- 1.3. Among the 51 patients (53.9%) in group 1, one required prostaglandins and we performed 10 cesarean sections. In group 2, the mean Bishop score at the 3rd day was 4.4 +/- 1.3 (P < 0.0001). Twenty-four patients required prostaglandins (P < 0.0001) and we performed 17 cesarean sections (P = 0.01). The number of cesarean sections increased with the dose of prostaglandins (P = 0.025). We observed no maternal or fetal complications. DISCUSSION AND CONCLUSIONS: Mifepristone was successful in inducing labour spontaneously in over 50% of pregnancies after 41 weeks of gestation. In the other group, the probability of vaginal delivery was reduced especially when high doses of prostaglandins were required. After the use of mifepristone, we suggest to shorten the duration of prostaglandin administration (two applications of 2 mg dinoprostone) before performing cesarean section.