Post-void residual volume in labor: A prospective study comparing parturients with and without epidural analgesia

Background: This prospective, non-randomized study compared post-void residual volume in laboring and postpartum women with or without epidural analgesia. Methods: The study was conducted over 1 year with institutional review board approval. Parturients were recruited in early labor and self-selected to either the study (with epidural) or control (without epidural) group. Post-void residual volume was compared between groups, using transabdominal ultrasound during labor, and on postpartum day 1 and 2. Main outcome measure was intrapartum residual bladder volume. Results: Thirty patients were recruited to each group. During labor, residual bladder volume was significantly larger in the epidural group compared with the non-epidural group [median (range)] 240 (12-640), ml vs. 45 (13-250) ml, respectively, P < 0.001], but was similar on postpartum day 1 and 2. Twenty-five (83%) women with epidural analgesia required bladder catheterization during labor vs. one (3.3%) without (P < 0.0001). Conclusion: The greater post-void residual volume and increased inability to void in parturients with epidurals suggests that epidural analgesia plays a role in intrapartum urinary retention.