Does BMI Have an Impact on Endometriosis Symptoms and Endometriosis Types According to the #ENZIAN Classification?

Background/Objectives: The relationship between body mass index (BMI) and endometriosis symptoms or lesion types remains unclear. This study investigates the association between BMI and symptom severity as well as the anatomical distribution of endometriosis using the #ENZIAN classification. Methods: A retrospective analysis was conducted on 219 patients with histologically confirmed endometriosis who underwent laparoscopic surgery at a tertiary endometriosis center in 2021. Preoperative symptom data were collected using standardized questionnaires. Patients were grouped by BMI categories based on WHO criteria. Endometriosis was classified intraoperatively using the #ENZIAN system. Statistical analyses included chi-square tests and one-way ANOVA. Results: Patients with low/normal BMI (<25 kg/m², n = 150) reported significantly higher intensity of chronic pelvic pain (CPP) compared to those with overweight/obesity (≥25 kg/m², n = 69; p = 0.0026). When stratified into four BMI groups, dyspareunia was significantly less frequent in obese patients (p = 0.0306), and high-intensity CPP was less common in both underweight and obese categories compared to normal-weight patients (p = 0.0069). Infertility rates increased significantly with higher BMI (p = 0.00001). No significant differences in the distribution of endometriosis lesions across #ENZIAN compartments were observed in relation to BMI. Conclusions: Our findings indicate that BMI does not significantly influence the anatomical distribution of endometriosis lesions as defined by the #ENZIAN classification, but it does correlate with some symptom intensity and infertility. These results suggest that while BMI may not predict disease localization, it plays a role in shaping the clinical phenotype of endometriosis.