Acquired and inherited thrombophilia in women with unexplained fetal losses

The purpose of this study was to investigate the possible role of inherited and acquired thrombophilia in women with unexplained abortions and intrauterine fetal death.

We included 75 women with >/=1 unexplained fetal loss, and 75 control subjects with at least 1 healthy term infant and without gestational complications. All of these women were tested for mutations of factor V Leiden, methylenetetrahydrofolate reductase, and prothrombin gene; deficiencies of antithrombin-III, protein C, and protein S; and the presence of antiphospholipid antibodies and fasting homocysteine concentration. A placental histologic study was also carried out.

Thirty-five percent of the 75 patients had thrombophilia (control subjects, 16%; P =.008; odds ratio, 2.78). This prevalence was more prominent in second and third trimesters (P =.0002; odds ratio, 6.3), and the presence of combined genetic defects was associated with intrauterine fetal death (P =.04; odds ratio, 12; 95% CI, 1.44-102). When we analyzed the overall gestations of the patients, we observed an increase of intrauterine fetal death in patients with thrombophilia (P =.01) and early pregnancy loss in patients without thrombophilia (P =.02). The analysis of the correlation between extensive placental infarctions and thrombophilic defects rendered values in the boundaries of significance (P =.05).

The significant high prevalence of biologic causes in patients with late fetal loss suggests that a study of thrombophilia should be carried out, together with an assessment of a preventive treatment.