Changes in plasma coagulation markers with prophylactic treatment of low molecular weight heparin after cesarean section.

Cesarean section has been identified as a major risk factor for thromboembolism, and additional risk factors place some women at a much higher risk during puerperium. Recently, low molecular weight heparins (LMWHs) have been used for thromboembolism prophylaxis after cesarean section. We investigated the effect of risk factors of thromboembolism on plasma coagulation markers when the LMWH dalteparin was used following cesarean section. Twenty-four women with risk factors other than cesarean section (high-risk group) and 13 without any other risk factors (low-risk group) received dalteparin starting immediately after cesarean section until the patients were mobilized. Sixteen women without any other risk factors served as controls (control group). Activated partial thromboplastin times, thrombin-antithrombin complex, alpha (2)-plasmin inhibitor-plasmin complex, and activated factor X levels were not different between the high-risk and the low-risk groups. However, fibrinogen/fibrin degradation products D-dimer levels were higher in the high-risk group than in the low-risk and control groups on days 3 and 7 after cesarean section. These findings suggest that the D-dimer levels may be elevated by some risk factors and that postoperative D-dimer determinations may be useful in assessing the risk of thromboembolism during LMWH treatment after cesarean section.