A randomized controlled trial of differing doses of postcesarean enoxaparin thromboprophylaxis in obese women

Objective:to compare two enoxaparin dosing strategies at achieving prophylactic anti-xa levels in women with a body mass index (bmi) ⩾35 (kg m−2) postcesarean delivery.study design:women with bmi ⩾35 were randomized to receive prophylactic enoxaparin at a fixed dose of 40 mg daily or weight-based dosing of 0.5 mg kg−1 twice daily. the primary outcome was the proportion of subjects with peak anti-xa levels in the prophylactic range of 0.2 to 0.6 iu ml−1.result:from august 2013 through february 2014, 84 demographically similar women completed the protocol. in the weight-based group, 88% (37/42) of the women reached prophylactic anti-xa levels versus 14% (6/42) in the fixed dose group (odds ratio 44.4, 95% confidence interval 12.44, 158.48, p<0.001). no anti-xa level exceeded 0.48 iu ml−1. there were no venous thromboembolic or bleeding events requiring reoperation or transfusion in either group.conclusion:compared with fixed dosing daily, weight-based dosing twice daily more effectively achieved prophylactic anti-xa levels without reaching the therapeutic range.