Body mass and risk of complications after hysterectomy on benign indications.

BACKGROUND: This study examines BMI in relation to risk of complications after hysterectomy on benign indications, and explores whether any associations vary by route of surgery.

METHODS: In this cohort study, we included data on health and lifestyle collected prospectively for all hysterectomy referrals for benign indications in Denmark from 2004 to 2009. Logistic regression was used to investigate relationship between BMI and complications reported at surgery or during the first 30 days after surgery. RESULTS; Of the 20 353 women with complete data, 6.0% had a BMI < 20 kg/m(2), 31.9% with BMI between 25 and 30 kg/m(2) (classified as overweight) and 17.5% with a BMI ≥ 30 kg/m(2) (categorized as obese). The overall rate of complications was 17.6%, with bleeding being the most common specific complication (6.8%). After adjustment for age, ethnicity, education, indication for surgery, uterus weight, use of prophylaxis, American Society of Anaesthesiologists classification, co-morbidity status and route of hysterectomy, obesity was associated with an increased risk of heavy bleeding during surgery [odds ratio (OR) = 3.64 (2.90-4.56)], all bleeding complications [OR = 1.27 (1.08-1.48)] and infection [OR = 1.47 (1.23-1.77)]. The risk of all bleeding complications [OR = 1.48 (1.28-1.82)] and re-operation [OR = 1.66 (1.26-2.17)] were also increased among women with a BMI < 20. This U-shaped relation between BMI and bleeding, and the association between high BMI and infections were only seen for the abdominal route [abdominal hysterectomy (AH)]. The risk of infections was elevated among women with BMI<20 who underwent laparoscopic surgery [laparoscopic hysterectomy (LH)]. CONCLUSIONS; Obesity increases the risks of bleeding and infections after AH. A BMI below 20 seems to increase the risks of bleeding and infection after AH and LH, respectively.