Definition of Failed Induction of Labor and Its Predictive Factors: Two Unsolved Issues of an Everyday Clinical Situation

Objective: The objectives of this review were to identify the predictive factors of induction of labor (IOL) failure or success as well as to highlight the current heterogeneity regarding the definition and diagnosis of failed IOL. Materials and Methods: Only studies in which the main or secondary outcome was failed IOL, defined as not entering the active phase of labor after 24 h of prostaglandin administration ± 12 h of oxytocin infusion, were included in the review. The data collected were: study design, definition of failed IOL, induction method, IOL indications, failed IOL rate, cesarean section because of failed IOL and predictors of failed IOL. Results: The database search detected 507 publications. The main reason for exclusion was that the primary or secondary outcomes were not the predetermined definition of failed IOL (not achieving active phase of labor). Finally, 7 studies were eligible. The main predictive factors identified in the review were cervical status, evaluated by the Bishop score or cervical length. Discussion: Failed IOL should be defined as the inability to achieve the active phase of labor, considering Received: January 15, 2015 Accepted after revision: May 8, 2015 Published online: June 26, 2015 Núria Baños, MD, BCNatal – Barcelona Center for Maternal-Fetal and Neonatal Medicine, Hospital Clínic and Hospital Sant Joan de Déu Fetal i+D Fetal Medicine Research Center, IDIBAPS University of Barcelona, Sabino de Arana 1, ES–08028 Barcelona (Spain) E-Mail NBANOS @ clinic.ub.es © 2015 S. Karger AG, Basel 1015–3837/15/0383–0161$39.50/0