Transperineal ultrasound-based outcomes of postpartum pelvic floor recovery after elective cesarean section versus vaginal delivery: a systematic review and meta-analysis.

OBJECTIVE: To synthesize evidence on transperineal ultrasound-based and clinically relevant postpartum pelvic floor outcomes following elective cesarean section delivery (CSD) compared with vaginal delivery (VD). METHODS: Observational studies (cohort, case-control, and cross-sectional studies) comparing elective CSD with VD were included. Outcomes were pelvic floor muscle strength (PFMS), posterior bladder angle (PBA), bladder neck descent (BND), postpartum SUI, and POP. Risk of bias was assessed using ROBINS-I, and certainty of evidence was evaluated using the GRADE framework. RESULTS: Twelve studies contributed to at least one outcome-specific quantitative or narrative synthesis. Five studies were included in the PFMS analysis. Because the included studies used different PFMS measurement methods and scales, PFMS was analyzed using standardized mean difference (SMD) rather than mean difference. Reported elective CSD showed a non-significant trend toward higher PFMS compared with VD (SMD = 0.27, 95% CI -0.05 to 0.60, p = 0.10, I 2 = 74.75%). PBA did not differ significantly between delivery modes (3 studies, MD = -3.26, 95% CI -7.09 to 0.56, p = 0.09, I 2 = 71.85%). BND was reported in only two studies and was summarized narratively. Reported elective CSD was associated with a lower risk of postpartum SUI than VD (6 studies, RR = 0.47, 95% CI 0.38 to 0.59, p < 0.001, I 2 = 46.6%). The POP estimate also favored reported elective CSD (4 studies, RR = 0.56, 95% CI 0.35 to 0.91, p = 0.018, I 2 = 74.0%), but was less robust because it was based on four studies with substantial heterogeneity. Labor exposure before cesarean delivery was incompletely reported in most studies, and postpartum assessment timing varied across studies. CONCLUSIONS: Current observational evidence suggests that reported elective CSD may be associated with a lower risk of postpartum SUI compared with VD. The evidence for POP also favored reported elective CSD, but was less robust. Evidence for PFMS and ultrasound-derived anatomical parameters remains uncertain. These findings should not be used as the sole basis for delivery-mode counseling. GRADE certainty was low for the SUI association and very low for PFMS, PBA, BND, and POP.