Multimodal Pelvic Floor Ultrasound Parameters Associated with Postpartum Pelvic Floor Dysfunction: A Retrospective Study.

Research on multimodal ultrasound parameters associated with postpartum pelvic floor dysfunction (PFD) across resting, maximal contraction, and Valsalva states remains limited. This retrospective study assessed these parameters in 172 patients examined between January 2022 and June 2025. After stratification into PFD and non-PFD groups, 1:1 propensity score matching (PSM) yielded 160 patients (80 per group) for analysis. Ultrasound parameters were evaluated across the three functional states. Logistic regression identified independent factors associated with PFD, and receiver operating characteristic (ROC) curve analysis assessed model performance. After PSM, baseline characteristics were comparable between groups (all p > 0.05). Compared with the non-PFD group, the PFD group had a larger resting levator ani hiatus area, a more inferior bladder neck position, and lower levator ani muscle thickness (all p < 0.001). During maximal contraction, the hiatus area reduction percentage and bladder neck elevation were lower. During the Valsalva maneuver, the hiatus area, bladder neck mobility, and most distal prolapse position were greater, and levator ani avulsion was more frequent (all p < 0.001). A larger resting levator ani hiatus area, lower resting muscle thickness, a lower hiatus area reduction percentage, greater bladder neck mobility during the Valsalva maneuver, and levator ani avulsion were independently associated with postpartum PFD (all p < 0.001). The five-parameter model had an area under the curve (AUC) of 0.870 (95% confidence interval, 0.815-0.926), with 91.3% sensitivity and 88.8% specificity. The model showed favorable internal fitting performance in the development dataset. Because independent validation was not performed, the findings should be considered hypothesis-generating; applications in clinical screening and individualized intervention remain unproven.