Postpartum sedentary behaviour and pelvic floor support: A prospective cohort study.

We evaluated the association between sedentary time and pelvic floor support in primiparas delivered vaginally. The 532 participants (29.2 ± 4.9 years) wore wrist accelerometers 6 months postpartum to assess sedentary time, light physical activity (LPA) and moderate to vigorous physical activity (MVPA). We assessed pelvic floor support 1 year postpartum, considered worse if vaginal walls or apex prolapsed to or beyond the hymen. We used multivariable isotemporal substitution analyses to determine the prevalence of worse support when replacing sedentary time with equal time spent in either LPA or MVPA. In 1 year, 9.4% demonstrated worse pelvic floor support. Decreasing sedentary time by 30 min/day with a concomitant increase in MVPA, controlling for LPA, was associated with increased prevalence of worse support (PR 1.43 (95% CI 1.15, 1.77), P  < 0.01). Decreasing the sedentary time by 30 min/day with a concomitant increase in LPA, controlling for MVPA, was not significant (PR 0.89 (95% CI 0.80, 0.99), P  = 0.04, > pre-set alpha of 0.02). Increasing MVPA while decreasing LPA, controlling for sedentary time, also increased the prevalence of worse support (PR 1.66 (95% CI 1.28, 2.16), P  < 0.001). In conclusion, decreasing sedentary time increased the prevalence of worse pelvic floor support when replaced by MVPA, but not LPA.