The Association Between Sitting Delivery During the Second Stage of Labor and Pelvic Floor Function in Primiparas: A Prospective Cohort Study

Background/Objectives: Pregnancy and childbirth are independent risk factors for pelvic floor injury. The choice of delivery position, as an interventionable factor during labor, has received much attention. This study aimed to assess the impact of sitting delivery on pelvic floor function by observing the outcomes of the perineum, duration of the second stage of labor, integrity of pelvic floor structure, and postpartum pelvic floor function. The goal was to provide scientific evidence for optimizing delivery management and reducing the risk of pelvic floor injury. Methods: This was a non-randomized study (based on patient choice). A total of 222 primiparous women who delivered at our hospital from February to August 2023 were selected and divided into the control group (n = 88) and the sitting group (n = 134). The second stage of labor in the control group was delivered in the traditional bladder lithotomy position, while the sitting group delivered in a sitting position. The duration of the second stage of labor, delivery method, degree of perineal laceration, postpartum 2 h bleeding volume, and the occurrence of urinary incontinence and sexual dysfunction 1 year after delivery were observed in both groups. Results: The rate of perineal lateral incision in the sitting group was lower than that in the control group (24.6% vs. 48.9%, aOR = 0.37, p < 0.001); the adjusted mean difference in second-stage duration was −11.65 min (95% CI: −25.35 to 2.05, p = 0.095), indicating no statistically significant difference after adjustment. In unadjusted subgroup analysis, a larger point estimate for reduction was observed in women aged < 30 years (median difference −16.0 min, p = 0.033), but the interaction test was not significant. For urinary incontinence and sexual dysfunction, there were no statistically significant differences between the two groups. Conclusions: Sitting delivery was associated with a lower episiotomy rate and, in unadjusted analysis, a shorter second stage (although the adjusted difference was not significant), and it did not increase the incidence of urinary incontinence or sexual dysfunction at one year postpartum.