Prevalence of factor V G1691A (Factor V-Leiden) and prothrombin G20210A gene mutations in a recurrent miscarriage population

Factor V G1691A (FV-Leiden) and prothrombin G20210A mutations are major inherited risk factors for venous thrombosis. Recently, it was suggested that both mutations, through stimulation of venous and placental thrombosis events, were strongly associated with recurrent idiopathic miscarriages, although other studies disputed such a link. The aim of this study was to determine the prevalence of prothrombin G20210A and factor V G1691 A (R506Q, FV-Leiden) mutations in women with recurrent idiopathic abortions and to recommend management for high-risk mutation carriers. One hundred ten women with two or more consecutive unexplained first-trimester miscarriages (mean age +/- SD, 32.3 +/- 5.3) were compared to 67 parous women with uncomplicated pregnancies (mean age +/- SD, 33.9 +/- 7.3) (P = 0.134) from the same ethnic background. The presence or absence of the prothrombin G20210A and FV-Leiden mutations was assessed by PCR and RFLP analysis, using HindIII and MnlI digestion, respectively. In women with primary habitual abortion, 45 (40.91%) carried the FV-Leiden mutation, of whom 7 were in the homozygote and 38 were in the heterozygote states, and 15 (13.64%) carried the prothrombin G20210A mutation all as heterozygotes, compared to 16.42% and 2.99% carrier rates among controls, respectively, all of whom were heterozygote carriers. Of the other risk factors analyzed, smoking (OR 1.76; 95% CI = 0.79-3.94) was more prevalent in habitual aborters compared to controls. Both FV-Leiden and factor II G20210A mutations are major inherited risk factor associated with primary recurrent miscarriages. Women with a family or personal history of thrombosis should be screened before or early in the pregnancy for FV-Leiden and factor II G20210A mutations.