The effect of epidural analgesia on labor progress and outcome in nulliparous women

Objective. The present study was designed to investigate the influence of epidural analgesia on labor progress and outcome in nulliparous women. Methods. A population-based study comparing women with and without epidural analgesia was conducted. Deliveries occurred during 1988-2006 at the Soroka University Medical Center. A multivariable logistic regression model with backward elimination was constructed to control for confounders. Results. During the study period there were 39 498 deliveries; epidural analgesia was given in 9960 (25.2%) of these. Using a multivariable analysis with backward elimination, the following conditions were significantly associated with the use of epidural analgesia: advanced maternal age, oligohydramnios, premature rupture of membranes, induction of labor, and Jewish (vs. Bedouin) ethnicity. These patients were more likely to deliver by cesarean delivery (CD; OR=1.4, 95% CI 1.3-1.5; p<0.001) and vacuum extraction (OR=1.5, 95% CI 1.4-1.7; p<0.001). After controlling for possible confounders such as macrosomia, failed induction, hypertensive disorders, gestational diabetes, maternal age, labor dystocia, and ethnicity, epidural analgesia was not found to be an independent risk factor for CD but rather a protective factor (OR=0.9, 95% CI 0.8-0.9; p=0.038). When vacuum extraction was the outcome variable, epidural analgesia was documented as an independent risk factor (OR=1.1, 95% CI 1.01-1.3; p=0.04). Conclusions. Epidural analgesia in nulliparous parturients increases the risk for labor dystocia and accordingly is an independent risk factor for vacuum extraction. Nevertheless, it does not pose an independent risk for cesarean delivery.