Introduction This study examines preoperative Body Mass Index (BMI) in relation to risk of complications after hysterectomy on benign indications, and explores whether any associations vary by route of surgery.
Methods A cohort study which includes data on health and lifestyle collected prospectively by the surgeon whenever a woman was referred for hysterectomy on a benign indication in Denmark from 2004 to 2009. Logistic regression was used to investigate associations of BMI with complications reported at surgery or during the first 30 days postoperative.
Results Of the 20 353 women with complete data, 6.0% had a BMI <20 kg/m2, 31.9% with BMI between 25 and 30 kg/m2, were classified as overweight and 17.5% as obese with a BMI≥30 kg/m2. The rate of complications was 17.6% with bleeding being the most common specific complication (6.8%). After adjustment for age, ethnicity, education, smoking, indication for surgery, uterus weight, ASA-classification, co-morbidity status, and route of hysterectomy, obesity was associated with increased risk of bleeding (OR=1.27 (1.08–1.48)) and infections (OR=1.47 (1.23–1.77). The risks of bleeding (OR=1.48 (1.28–1.82)) and re-operation (OR=1.67 (1.28–2.17)) were also increased among women with a BMI<20. The U-shaped relation between BMI and bleeding, and between high BMI and infections were only seen for the abdominal route. The risk of infections was elevated among women with BMI <20 who underwent laparoscopic surgery.
Conclusion Obesity increases the risks of bleeding and infections after abdominal hysterectomy. A BMI below 20 seems to increase the risks of bleeding and infection after abdominal and laparoscopic hysterectomy, respectively.