Maternal position during the second stage of labor and maternal-neonatal outcomes in nulliparous women: a retrospective cohort study.

Background: The existing evidence is insufficient to draw conclusions about the association between maternal position in labor and obstetrical outcomes.

Objective: This study aimed to evaluate the effects of different maternal positions during the second stage of labor among women with and those without epidural analgesia on important obstetrical outcomes including perineal damage.

Study Design: In this retrospective cohort study, we collected data of women who delivered vaginally over a 2-year period. The associations between maternal and gestational characteristics and several obstetrical outcomes were analyzed. We considered perineal damage as the primary outcome. Secondary outcomes were the incidence of operative vaginal births, duration of fetal descent, intrapartum blood loss, and 1-minute and 5-minutes Apgar scores.

Results: A total of 2240 nulliparous, at-term pregnancies were included. Of those, 76.9% gave birth in a supine position and 23.1% gave birth in alternative positions. The results showed that regardless of the use of epidural analgesia, nonsupine positions in the second stage of labor are associated with a significant reduction in the risk of both episiotomy and perineal damage to any degree (<.0001) and to a reduction in the duration of fetal descent (Spearman rho, 9.17; confidence interval, 3.07-15.32; =.003). No statistically significant differences were found in the 1-minute and 5-minutes Apgar score between the 2 groups.

Conclusion: Our results show that nonsupine positions in the second stage of labor and at the time of birth are associated with a significant increase in having an intact perineum and a reduction in any perineal trauma and in the need for an episiotomy regardless of the use of epidural analgesia.