Body mass index influences the risk of reoperation after first-time surgery for pelvic organ prolapse. A Danish cohort study, 2010–2016

Introduction and hypothesis: The aims of this study were to evaluate the impact of body mass index (BMI) on the risk of reoperation for pelvic organ prolapse (POP) up to 5 years after first-time surgery. Materials and methods: This nationwide register-based study includes first-time POP surgery in 2010 through 2016. The cumulative incidence proportions of reoperation were analyzed in a Cox regression model and described using Kaplan-Meier plots stratified in BMI categories. Results: A total of 28,533 first-time procedures were performed in 22,624 women; 76.6% had single-compartment repair. The 1- and 5-year reoperation rate within the same compartment was 2.6% and 6.1% respectively for women with BMI < 25, and for women with BMI > 35 it was 3.7% and 11.2 respectively. In the anterior compartment there was a significantly increased adjusted hazard ratio for reoperation in the same compartment with increasing BMI (reference group BMI < 25), BMI 30–34.9 with an aHR = 1.34 (CI 95% 1.04–1.71) and BMI ≥ 35 aHR = 1.77 (CI 95% 1.17–2.67). The 1- and 5-year reoperation rate in an adjacent compartment was 0.6% and 1.6% respectively for women with BMI < 25, and for women with BMI > 35 it was 1.0% and 4.4 respectively. For reoperation in an adjacent compartment the adjusted results were BMI 30–34.9 aHR = 1.64 (95% CI 1.05–2.56) and BMI > 35 aHR = 2.64 (95% CI 1.36–5.14) when the first-time operation was in the anterior compartment. Conclusions: If the woman had BMI > 35 and first-time surgery was in the anterior compartment, she had an almost doubled risk of reoperation within 5 years both in the same compartment and in an adjacent compartment compared to women with BMI < 35. In the apical and posterior compartment there was a trend towards increasing risk of reoperation with increasing BMI, although with a broad confidence interval.