Evaluation of the Impact of the Thromboprophylactic Dose of LMWH on Coagulation in Pregnant Women.

The project aims to clarify the effect of the thromboprophylactic LMWH dose on coagulation in pregnant women just before birth, at the period of maximal physiological hypercoagulable state and with high risk of thromboembolism, the most common cause of maternal mortality in developed countries. Although LMWH are now routinely administered as prevention of thromboembolism, their effect on coagulation in pregnant women was not yet studied. The doses of LMWH in pregnancy are only derived in terms of coagulation from totally different groups of patients (surgical, orthopedic). We therefore will map the effect of thromboprophylactic LMWH dose on coagulation in pregnant women using recently available methods, especially a complex examination of coagulation within 24 h after LMWH application using thrombelastography, including examination with heparinase, and monitoring the effect of LMWH by measuring antiXa and TGT (thrombin generation time) activity. Based on these results we will also evaluate the possible influence of LMWH prophylaxis on the risk of spinal haematoma during neuraxial analgesia/anesthesia for delivery/Caesarean section. On the basis of our pilot results we can presume the current dosage of LMWH in pregnant women is inadequate and that it would be appropriate to adjust presently used dosage. At the same time we want to prove that the standard LMWH thromboprophylaxis in pregnant women does not increase the risk of spinal haematoma during neuraxial blockade. In both situations the targeted outcome is to increase the safety of pregnant women.