Prevalence of parental thrombophilic defects after fetal death and relation to cause.

OBJECTIVE To estimate whether parental thrombophilic defects after fetal death, either acquired or inherited, were more prevalent than in the normal population and to estimate associations between these thrombophilic defects and different fetal death causes. METHODS In a multicenter, prospective cohort study of 750 fetal deaths, we tested couples for antithrombin, protein C, total and free protein S, and von Willebrand factor (vWF) plasma levels. Mothers' values were compared with reference values in gestational age-matched healthy pregnant women, and fathers were compared with healthy men. Prevalence of factor V Leiden, prothrombin G20210A mutation, and lupus anticoagulant were compared with the normal population. A panel classified death cause. RESULTS More women with fetal death had decreased antithrombin (16.8%, P<.001) and protein C (4.0%, P=.03) and increased vWF (15.5%, P<.001) plasma levels than healthy pregnant women (2.5%). However, compared with normal ranges in the nonpregnant population, we only observed more women with increased vWF (12.4%, P<.001). More fathers had decreased free protein S (6.3%, P<.001) and elevated vWF (12.1%, P<.001) than healthy men (2.5%). Prevalence of inherited thrombophilias was not higher in couples with fetal death than in the population. Neither inherited nor acquired maternal or paternal thrombophilic defects were associated with the main cause of death. Of placental causes, abruption and infarction were associated with acquired maternal defects. CONCLUSION Except for vWF and paternal free protein S, acquired and inherited thrombophilic defects were not more prevalent after fetal death. Routine thrombophilia testing after fetal death is not advised. LEVEL OF EVIDENCE II.