Prevalence of factor V Leiden is not increased in women with recurrent miscarriage

The purpose of this study was to determine if there is an increased prevalence of the thrombophilic genetic mutant factor V Leiden in patients with recurrent miscarriage. Functional assays were conducted for activated protein C resistance and genetic detection of factor V Leiden in 100 women with recurrent miscarriage compared with a control group. The prevalence of factor V Leiden in patients was 6/100 (6%) compared with 3/85 (3.5%) in controls. The difference was not statistically significant. Antithrombotic prophylaxis with heparin and/ or aspirin in a subsequent pregnancy in five of the six patients with factor V Leiden was associated with maintenance of pregnancy and delivery of a live, healthy, full-term infant in four. We have been unable to demonstrate a statistically significant increased prevalence of factor V Leiden in women with recurrent miscarriage. If antithrombotic prophylaxis in pregnancy can be shown by controlled therapeutic trial to prevent miscarriage in these patients, identification of this subgroup would be important.