Maternal Thrombophilia and Recurrent Miscarriage – Is There Evidence That Heparin is Indicated as Prophylaxis against Recurrence?

BACKGROUND: Recurrent miscarriage, also referred to as recurrent spontaneous abortion (RSA), affects 1 – 5% of couples and has a multifactorial genesis. Acquired and congenital thrombophilia have been discussed as hemostatic risk factors in the pathogenesis of RSA. METHOD: This review article was based on a selective search of the literature in PubMed. There was a special focus on the current body of evidence studying the association between RSA and antiphospholipid syndrome and hereditary thrombophilia disorders. RESULTS: Antiphospholipid syndrome (APS) is an acquired autoimmune thrombophilia and recurrent miscarriage is one of its clinical classification criteria. The presence of lupus anticoagulant has been shown to be the most important serologic risk factor for developing complications of pregnancy. A combination of low-dose acetylsalicylic acid and heparin has shown significant benefits with regard to pregnancy outcomes and APS-related miscarriage. Some congenital thrombophilic disorders also have an increased associated risk of developing RSA, although the risk is lower than for APS. The current analysis does not sufficiently support the analogous administration of heparin as prophylaxis against miscarriage in women with congenital thrombophilia in the same way as it is used in antiphospholipid syndrome. The data on rare, combined or homozygous thrombophilias and their impact on RSA are still insufficient. CONCLUSION: In contrast to antiphospholipid syndrome, the current data from studies on recurrent spontaneous abortion do not support the prophylactic administration of heparin to treat women with maternal hereditary thrombophilia in subsequent pregnancies. Nevertheless, the maternal risk of thromboembolic events must determine the indication for thrombosis prophylaxis in pregnancy.