Maternal thrombophilias are not associated with early pregnancy loss

We investigated the association between inherited and acquired maternal thrombophilias and adverse pregnancy events. A cohort of 491 patients with a history of adverse pregnancy outcomes was evaluated for activated protein C resistance, factor V Leiden and prothrombin G20210A mutations, hyperhomocysteinemia, deficiencies of antithrombin, protein C and S and both anticardiolipin antibodies and lupus anticoagulants. The study had an 80% power to detect a 15% difference in the prevalence of thrombophilia for 1(st) trimester loss. In our high-risk cohort the presence of 1 maternal thrombophilia or more than one thrombophilia were found to be protective of recurrent losses at < 10 weeks (1 thrombophilia: OR: 0.55, 95% CI: 0.33-0.92; > 1 thrombophilia: OR: 0.48, 95%CI:0.29-0.78). In contrast, the presence of maternal thrombophilia(s) was modestly associated with an increased risk of losses > 10 weeks (1 thrombophilia: OR:1.76, 95%CI: 1.05-2.94, >1 thrombophilia: OR:1.66, 95%CI:1.03-2.68). Women who experienced only euploid losses were not more likely to have an identified thrombophilia than women who experienced only aneuploid losses (OR 1.03; 0.38-2.75). The presence of maternal thrombophilia was associated with an increased risk of fetal loss after 14 weeks, fetal growth restriction, abruption and preeclampsia. There was a significant "dose-dependent" increase in the risk of abruption (OR:3.60, 95%CI: 1.43-9.09) and preeclampsia (OR:3.21, 95%CI:1.20-8.58). In conclusion, these data indicate maternal thrombophilias are not associated with pregnancy wastage prior to 10 weeks of gestation.