Thromboprophylaxis and pregnancy outcomes in asymptomatic women with inherited thrombophilias

Objective Our objective was to evaluate the effect of thromboprophylaxis on pregnancy outcomes in asymptomatic women with inherited thrombophilias. Study Design This was a retrospective cohort study of asymptomatic pregnant women with inherited thrombophilias. Medical records were reviewed for pregnancy events, diagnosis of thrombophilias, and management in subsequent pregnancies. Outcomes in women who were and were not treated with thromboprophylaxis were compared using Fisher's exact test and logistic regression. Results Fifty-three women had 75 pregnancies subsequent to their diagnosis of thrombophilia. Women treated with heparin had similar rates of live births (86% vs 82%; P = .8, Fisher's exact test) as those not treated. The odds ratio of live birth in all pregnancies for women treated with heparin was compared with untreated women and was 1.9 (95% confidence interval, 0.5-6.3). Conclusion Pregnancy outcomes are often good in asymptomatic women with thrombophilias in the absence of treatment. Treatment of these women during pregnancy should be considered investigational.