(253) Self-reported pelvic floor symptoms one-year after an OASI in relation to maternal body mass index

The aim of this study was to evaluate self-reported pelvic floor symptoms one-year after an obstetric anal sphincter injury (OASI) in primiparous women grouped according to body mass index (BMI). We hypothesized that dyspareunia, urinary incontinence (UI) and anal incontinence (AI) were more common in overweight and obese women compared to normal weight women one year postpartum.

Study Design: A population-based cohort study including 6595 primiparous women, with an OASI, who were delivered in Sweden between 2014 and 2019. Pre-pregnancy data and information from the one-year follow up questionnaire were retrieved from the Swedish Perineal Laceration Registry. Uni- and multivariate analyses were used to compare normal-weight (BMI ≤ 24.9), overweight (25.0-29.9) and obese (≥ 30) women in regard to self-reported prevalence of dyspareunia, UI and AI one-year postpartum.

Results:

Overweight and obese women had a decreased risk for dyspareunia compared with normal weight women, (aOR 0.82 CI 0.68-0.98) and (aOR 0.71 CI 0.54-0.93), respectively. The absolute rate of dyspareunia was 41% among normal weight 38% among overweight, and 33% in the obese group. In the univariate analyses episiotomy and grade of anal sphincter injury did not affect the risk for dyspareunia.  There was an increased risk for UI among overweight (aOR 1.51 CI 1.11-2.04) and obese women (aOR 2.82 CI 1.94-4.12) compared with normal weight women. The risk for AI did not differ between the BMI groups.

Conclusion: Dyspareunia one year after an OASI was less common among overweight and obese women than in normal weight women. The risk for AI did not differ between the BMI groups while the risk for UI increased with increasing BMI. The new findings of a decreased risk for dyspareunia with increasing BMI and that AI was equally distributed over the BMI groups  one year after OASI is clinically relevant. One possible explanation could be that obese women have less levator muscle trauma due to more perineal fat tissue that might be protective during second stage of labor, although this must be further investigated.