Thromboembolic prophylaxis with low molecular weight heparin during pregnancy.
OBJECTIVE
The objective of this study was to show that low molecular weight heparin (LMWH) can be used in preventing veno-pulmonary thromboembolic diseases in pregnancy.


METHODS
Twenty-four women carrying 27 pregnancies with known risk of veno-pulmonary thromboembolic diseases in pregnancy were prophylactically treated with LMWH (dalteparin) during part of their pregnancy. Our therapeutic target was a plasma concentration of 0.20-0.50 anti-Xa U/ml measured 2-6 h after subcutaneous administration of LMWH into the abdominal wall. To obtain this anti-Xa activity the patients were given total doses of 2500-10,000 anti-Xa U daily. Monitoring of anti-Xa activity in patients receiving < or = 5000 U/day was not necessary.


RESULTS
Twelve out of the 24 women received LMWH at the time of delivery. Our biochemical assay could not show the presence of anti-Xa activity in the blood samples from the babies although it was possible to show anti-Xa activity in their mothers. In three out of 24 women, blood samples showed activation of coagulation. These patients were changed to the vitamin K antagonist phenindione.


CONCLUSIONS
None of the treated women showed any clinical or paraclinical signs of thromboembolic diseases during pregnancy or 6 weeks postpartum. All the babies were born healthy. None of the women had any side effects due to the treatment.
Rasmussen
C
C
Department of Coagulation, Gentofte Hospital, University of Copenhagen, Denmark.
Wadt
J
J
Jacobsen
B
B
D065427:Factor Xa Inhibitors; D005260:Female; D006495:Heparin, Low-Molecular-Weight / Q000493:pharmacokinetics / Q000627:therapeutic use*; D006801:Humans; D008431:Maternal-Fetal Exchange; D011247:Pregnancy; D011250:Pregnancy Complications, Hematologic / Q000097:blood / Q000453:epidemiology / Q000517:prevention & control*; D018566:Pregnancy, High-Risk; D011655:Pulmonary Embolism / Q000097:blood / Q000453:epidemiology / Q000517:prevention & control*; D012307:Risk Factors; D013924:Thrombophlebitis / Q000097:blood / Q000453:epidemiology / Q000517:prevention & control*
D065427:Factor Xa Inhibitors; D006495:Heparin, Low-Molecular-Weight