To cite this article: Alalaf SK, Jawad AK, Jawad RK, Ali MS, Al Tawil NG. Bemiparin for thromboprophylaxis after benign gynecologic surgery: a randomized clinical trial. J Thromb Haemost 2015; 13: 2161-7.Summary. Background: Venous thromboembolism (VTE) is the leading cause of mortality and morbidity in women following gynecologic surgery. Objectives: To determine the efficacy of a second-generation low molecular weight heparin (bemiparin) for thromboprophylaxis after benign gynecologic surgery. Methods: We performed a singleblind randomized controlled trial including women in the moderate-risk, high-risk and highest-risk groups for developing VTE after benign gynecologic surgery. Participants were randomized at a 1 : 1 ratio into parallel groups to receive either seven daily doses of 3500 IU of subcutaneous bemiparin or to a non-intervention group receiving standard rehydration and advice on ambulation. Participants were followed up for 7 days and 30 days postoperatively for symptomatic VTE, which was confirmed by compression Doppler ultrasound, magnetic resonance imaging, or computed tomographic pulmonary angiography, according to the type of VTE. Results: In total, 387 participants were randomized to the bemiparin group and 387 to the non-intervention group. The incidence of symptomatic VTE (deep vein thrombosis and pulmonary embolism) events was lower (0/377) in participants who received bemiparin than in those who received no pharmacologic intervention (12/380, 3.2%; 95% confidence interval [CI] 0.002-0.6). Logistic regression analysis showed significant associations between VTE and immobility (odds ratio [OR] 7.1; 95% CI 1.3-36.2), varicose veins (OR 16.8; 95% CI 3.1-76.2), and thrombophilia (OR 39.3; 95% CI 1.5-1006.7). There were no major bleeding events or side effects related to the use of bemiparin. Conclusions: Bemiparin was an effective thromboprophylactic agent for preventing venous thrombosis after benign gynecologic surgery.