Introduction and hypothesis: Childbirth pelvic floor trauma leads to pelvic floor disorders. Identification of significant injuries would facilitate intervention for recovery. Our objectives were to identify differences in pelvic floor appearance and function following delivery and patterns of normal recovery in women sustaining high-risk labor events.
Methods: We completed a prospective cohort study comparing women undergoing vaginal births involving risk factors for pelvic floor injury with women undergoing cesareans. Data were collected on multidimensional factors including levator ani muscle (LA) tears. Descriptive and bivariate statistics were used to compare the groups. We identified potential markers of pelvic floor injury based on effect size.
Results: Eighty-two women post-vaginal delivery and 30 women post-cesarean enrolled. The vaginal group had decreased perineal body length between early postpartum, 6 weeks (p < 0.001), and 6 months (p = 0.001). POP-Q points did not change between any time point (all p > 0.05). Measures of strength improved between each time point (all p < 0.002). When compared with cesarean delivery, women post-vaginal birth had longer genital hiatus and lower anterior and posterior vaginal walls (all p < 0.05). Based on theoretical considerations and effect sizes, those with Bp ≥0 cm, Kegel force ≤1.50 N, and/or an LA tear on imaging were considered to have significant pelvic floor injury. Using this definition, at 6 weeks, 27 (46.4%) women were classified as injured. At 6 months, 13 (29.6%) remained injured.
Conclusions: We propose that pelvic floor muscle strength, posterior vaginal wall support, and imaging consistent with LA tear are potential indicators of abnormal or prolonged recovery in this cohort with high-risk labor events.
Keywords: Birth injury; Birth recovery; Levator ani injury; Vaginal birth.