|April 2004 · Vol. 16, No. 4
Anticoagulation in pregnancy:
Q&A on low molecular weight heparin
A discussion of the accumulating evidence that low molecular weight heparin may be the safest and most effective anticoagulant for gravidas.
Dr. Emery is director of perinatal ultrasound, department of obstetrics and gynecology, section of maternal-fetal medicine, Cleveland Clinic Foundation,
Low molecular weight heparin appears to be as safe as unfractionated heparin in pregnancy, with longer-lasting effects and reduced need for monitoring. Both the American College pregnancy with appropriate counseling.
Although warfarin is the anticoagulant of choice in the nonpregnant state, it crosses the placenta and has been linked to structural birth defects known as “warfarin embryopathy.”
A single subcutaneous, prophylactic 40-mg dose of the low molecular weight heparin enoxaparin costs about $30, compared with about $1 for an equivalent dose of unfractionated heparin.
What are the attributes of the ideal anticoagulant in pregnancy? Low molecular weight heparin fills the bill in many ways: It is safe for both mother and fetus, as effective in pregnancy as in the nongravid population, and side effects are minimal. It also has a favorable dosing route and interval, with less need for monitoring than with unfractionated heparin (UH).
In other ways, low molecular weight heparin (LMWH) is distinctly inferior. This article describes its strengths and weaknesses, addressing 10 common clinical questions.