Prediction of successful labor induction by evaluation of maternal symptoms at an early stage of the misoprostol induction protocol

Objective: This prospective observational study evaluated maternal symptoms and characteristics that predict successful labor induction with oral misoprostol. Methods: A total of 244 consecutive women undergoing labor induction voluntarily completed a questionnaire about subjective sensations and pain scores during the induction protocol. Maternal and neonatal characteristics were collected retrospectively from patient files. On the first day of induction, oral misoprostol (50 μg) every 4 h up to three doses was used. Results: A total of 46% of the parturients delivered or reached the active phase of labor 24 h after the initial dose of misoprostol (ID). In the whole study, 87% of the women delivered vaginally. In multivariable analysis, rupture of membranes, cervical dilatation before the initial dose, maternal sensation of painful contractions at 8 h after the initial dose, and gestational age, were found to be associated with successful labor induction. Conclusions: Maternal sensation of painful contractions 8 h after an ID is an independent predictive factor of successful labor induction (defined as delivery or active phase of labor 24 h after beginning of induction). Other independent predictive factors are rupture of membranes, cervical dilatation before the initial dose, and gestational age.