The risk of pregnancy-related venous thromboembolism in women who are homozygous for factor V Leiden

The risk of venous thromboembolism (VTE) is increased in pregnancy and duri ng the post-partum period, The absolute risk for pregnancy-related VTE in h eterozygous women with the factor V Leiden mutation is approximately 2%, bu t studies on this risk for homozygous women show conflicting results. In a retrospective family study, we found that the risk of pregnancy-related VTE in women with a symptomatic first-degree relative was 17% per pregnancy (9 5%CI4.7-37.4). Anticoagulant prophylaxis during the post-partum period appe ars to be indicated in asymptomatic homozygous women from symptomatic kindr ed, whereas this could be decided on an individual basis during pregnancy.