(HealthDay News) — Weight-based dosing of enoxaparin is more effective than BMI-based dosing for venous thromboembolism prophylaxis among morbidly obese women after cesarean delivery, according to a study published in Obstetrics & Gynecology.

Rachael T. Overcash, MD, MPH, from the University of California, San Diego, and colleagues conducted a prospective sequential cohort study involving women with BMI of 40 or greater who underwent cesarean delivery.

Participants were randomly assigned to weight-based (42 women) or BMI-stratified (43 women) enoxaparin dosing to prevent venous thromboembolism formation.

The weight-based group had significantly higher concentrations of anti-Xa compared with the BMI-stratified group (0.29 IU/mL vs. 0.17 IU/mL), according to the researchers. Eighty-six percent of the weight-based dosing group and 26% of the BMI-stratified dosing group had anti-Xa concentrations within the prophylactic range. 

None of the patients met the threshold for venous thromboembolism prophylaxis (anti-Xa concentration of 0.6 IU/mL or greater).

“In morbidly obese women after cesarean delivery, weight-based dosing of enoxaparin for venous thromboembolism prophylaxis is significantly more effective than BMI-stratified dosing in achieving adequate anti-Xa concentrations,” the researchers wrote.


  1. Overcash RT et al. Obstet Gynecol. 2015;125(6):1371-1376.