Pelvic floor muscle function before and after first childbirth

Abstract

Pregnancy and vaginal delivery are considered to be the main risk factors for development of pelvic floor dysfunction. We hypothesize that; 1) pelvic floor muscle (PFM) strength and endurance is significantly reduced by first delivery in general, and 2) changes in PFM strength and endurance are influenced by mode of delivery. Prospective repeated measures observational study. Thirty-six women completed the study. PFM function was measured as vaginal squeeze pressure. Paired t-test was used to compare PFM function before and after first childbirth for all participants as a group. One-way ANOVA was used to compare changes between different modes of delivery. A significant reduction in PFM strength (p < 0.0001) and endurance (p < 0.0001) was found for all participants after first childbirth. The reduction in strength was 20.1 hPa (CI:16.2; 24.1), 31.4 hPa (CI: 7.4; 55.2) 5.2 hPa (CI: -6.6; 17.0) in the normal vaginal, instrumental vaginal and acute cesarean groups, respectively. The difference was significant between normal vaginal and acute cesarean birth (p = 0.028) and instrumental vaginal and acute cesarean birth (p = 0.003). PFM strength is significantly reduced after vaginal delivery, both normal and instrumental, 6 to 12 weeks postpartum. Acute cesarean section resulted in significantly less muscle strength reduction.