Effect of Epidural Analgesia on the Duration of Induced Labor in Primiparous and Multiparous Women: A Retrospective Study

Context Epidural analgesia is commonly used during labor; however, its effect on the duration of labor, particularly in induced labor, remains unclear. Most previous studies have focused on spontaneous labor, with limited data on induced labor. Notably, very few studies have directly investigated how epidural analgesia affects labor duration and delivery outcomes in the setting of planned labor induction. Aims This study aimed to elucidate the effects of epidural analgesia on labor duration and delivery outcomes in primiparous and multiparous women undergoing labor induction. Settings and design A retrospective study was conducted at our hospital, including singleton pregnancies in which labor induction was performed between December 2020 and November 2021. Methods and materials Oxytocin and, if needed, oral prostaglandin E2 were used for labor induction. Epidural analgesia was administered using both single-shot and continuous infusion techniques. The primary outcome was the second stage of labor. Secondary outcomes included the duration of the first stage, rates of instrumental delivery, Kristeller maneuver, cesarean section, and Apgar scores at one and five minutes. Statistical analysis Continuous variables were analyzed using unpaired t-tests, and categorical data using chi-square tests. Propensity score matching was applied to adjust for confounding factors. Results Among 243 cases, epidural analgesia significantly prolonged the second stage of labor by 19 minutes in multiparous women (p=0.002), but had no effect in primiparous women (p=0.414). No significant differences were observed in any secondary outcomes. Results were consistent after propensity score matching. Conclusion The second stage of labor was not prolonged in primiparous women, while a modest prolongation occurred in multiparous women. However, there were no significant differences in other delivery-related outcomes, including rates of instrumental delivery or cesarean section.