Low molecular weight heparin treatment during subsequent pregnancies of women with inherited thrombophilia and previous severe pregnancy complications

OBJECTIVES: The aim of this study was to investigate the effect of low molecular weight heparin (LMWH) on incidence of adverse outcome in women with thrombophilias and previous severe pregnancy complications. MATERIALS AND METHODS: The study included 116 women with history of severe preeclampsia, fetal growth restriction (FGR) ≤5th percentile, severe placental abruption and stillbirth >20 weeks carrying factor V Leiden or prothrombin mutations, or protein S or C deficiency. Eighty-seven women referred to us for follow-up were treated with LMWH starting from weeks 5-15 (study group, A). Twenty-nine non-treated women referred only for delivery in our institution constituted the control group (B). RESULTS: The incidence of severe pregnancy complications in previous pregnancies was similar in both groups. Following treatment with LMWH, the incidence of severe preeclampsia was 4.6% in group A compared to 21% in group B, p = 0.007. The incidence of FGR was 2.3% in group A compared to 21% in group B, p = 0.03. The incidence of stillbirth or placental abruption was 0% in group A compared to 7% in group B, p = 0.06. The total incidence of adverse outcome was 7% in group A compared to 55% in group B, p = 0.0001. CONCLUSION: LMWH treatment of women with previous severe pregnancy complications and thrombophilias significantly reduces the rate of recurrence.