Effect of Maternal Weight on Wound and Pelvic Floor Complications After OASIs

Patients who sustain obstetric anal sphincter injuries (OASIs) are at an increased risk of perineal wound complications, and few studies have assessed the association between body mass index (BMI) and wound complications in patients who sustain OASIs.

The aim of this study was to compare the rates of wound and pelvic floor complications after OASIs based on (1) prepregnancy BMI and (2) gestational weight gain.

This was a retrospective cohort study of patients who attended a urogynecologist-led postpartum recovery clinic at a single academic institution following OASIs. Rates of wound and pelvic floor complications were compared between patients with a prepregnancy BMI <25 versus BMI ≥25 (calculated as weight in kilograms divided by height in meters squared). Comparisons were also made between patients with appropriate versus excessive gestational weight gain. Outcomes were compared using univariate and multivariate analyses.

Five hundred twenty-eight patients were included for analysis, 340 (64.4%) with a BMI <25 and 188 (35.6%) with a BMI ≥25. There were no significant differences in wound complications based on prepregnancy BMI (49.7% vs 42.6%, P=0.12) or gestational weight gain (48.4% vs 45.4%, P=0.48). In addition, there were no differences in urinary pelvic floor symptoms. However, patients with a pregnancy BMI ≥25 were less likely to experience fecal incontinence (adjusted odds ratio, 0.35; 95% CI, 0.14-0.87).

Neither prepregnancy BMI nor gestational weight gain was associated with wound complications or urinary pelvic floor symptoms. However, overweight and obese women were less likely to experience fecal incontinence after OASIs, which demonstrates the complexity of the pelvic floor and warrants further investigation.