THE RISK OF ABORTION AND STILLBIRTH IN ANTITHROMBIN-DEFICIENT, PROTEIN C-DEFICIENT, AND PROTEIN S-DEFICIENT WOMEN

Hereditary deficiencies of the naturally occurring anticoagulants are well recognized conditions predisposing to recurrent venous thromboemb olism. Since thrombotic phenomena have been implied as a cause of abor tion and stillbirth, we hypothesized that these deficiencies increase the risk of fetal demise. A group of 129 female subjects who had been pregnant at least once and who had a family member with documented ven ous thrombosis associated with a deficiency of AT, PC or PS were studi ed. We first assessed the obstetric history and subsequently determine d the deficiency status. In the 60 deficient subjects 42 (22.3%) of th e 188 pregnancies resulted in miscarriage or stillbirth as compared to 23 (11.4%) of the 202 pregnancies in the 69 non-deficient subjects. T he relative risk of abortion and stillbirth per pregnancy for deficien t women as compared to non-deficient women was 2.0 (95% C.I. 1.2-3.3).