Increased frequency of genetic thrombophilia in women with complications of pregnancy.

BACKGROUND

Obstetrical complications such as severe preeclampsia, abruptio placentae, fetal growth retardation, and stillbirth are associated with intervillous or spiral-artery thrombosis and inadequate placental perfusion. Whether these complications are associated with an increased frequency of thrombophilic mutations is not known.

METHODS

We studied 110 women who had one of the above-mentioned obstetrical complications and 110 women who had one or more normal pregnancies. The women were tested several days after delivery for the mutation of guanine to adenine at nucleotide 1691 [corrected] in the factor V gene (factor V Leiden), the mutation of cytosine to thymine at nucleotide 677 in the gene encoding methylenetetrahydrofolate reductase, and the mutation of guanine to adenine at nucleotide 20210 in the prothrombin gene. Two to three months after delivery the women were tested for deficiency of protein C, protein S, or antithrombin III and for the presence of anticardiolipin antibodies.

RESULTS

The mutation at nucleotide 1691 [corrected] in the factor V gene was detected in 22 of the women with obstetrical complications and in 7 of the women with normal pregnancies (20 percent and 6 percent, respectively; P=0.003). Twenty-four women with complications, as compared with nine women without complications, were homozygous for the C677T mutation in the gene encoding methylenetetrahydrofolate reductase (22 percent and 8 percent, respectively; P=0.005). The G20210A mutation in the prothrombin gene was found in 11 women with complications as compared with 3 women without complications (10 percent and 3 percent, respectively; P=0.03). Overall, 57 women with obstetrical complications had a thrombophilic mutation, as compared with 19 women with normal pregnancies (52 percent and 17 percent, respectively; P<0.001). Deficiency of protein S, protein C, or antithrombin III or anticardiolipin antibodies were detected in an additional 14 women with complications, as compared with 1 woman with a normal pregnancy (13 percent and 1 percent, respectively; P<0.001).

CONCLUSIONS

Women with serious obstetrical complications have an increased incidence of mutations predisposing them to thrombosis and other inherited and acquired forms of thrombophilia.