Thrombophilia, a tendency for excessive blood clotting, increases the risk of stillbirth because it interrupts the normal circulation of blood from the mother to the placenta. A team of researchers from two French institutions, the University Hospital in Nimes and the University of Montpellier 1, studied 160 pregnant women with genetic risk factors for thrombophilia (heterozygous factor V Leiden mutation, prothrombin G20210A mutation, or protein S deficiency) who had experienced one unexplained stillbirth at 10 weeks gestation or later prior to the study.
Treatment for the women began in their eighth week of the new pregnancy. Eighty participants were provided with 40 mg of enoxaparin by subcutaneous injection each day. Because of ethical concerns regarding providing pregnant women with a placebo, the researchers instead provided the other 80 participants with low-dose aspirin (100 mg daily), a commonly used blood thinner. All participants were also given 5 mg of folic acid a day as an additional preventive measure, beginning at least one month prior to conception and continuing throughout the pregnancy.
The results of enoxaparin use were impressive. Of the women on the drug, 86 percent had a normal live birth. In addition, no significant side effects were seen in these mothers or their newborns. The group taking aspirin suffered 57 pregnancy losses and only 29 percent of the women taking this medication had a successful birth.
The enoxaparin babies also weighed more than those born to the mothers taking aspirin; only 10 percent of enoxaparin newborns were small for their gestational age, compared with 30 percent of the as
Contact: Aislinn Raedy
American Society of Hematology