Increased rates of thrombophilia in women with repeated IVF failures.

BACKGROUND We investigated whether hereditary thrombophilia is more prevalent in women with recurrent IVF-embryo transfer failures. METHODS This case-control study was conducted in an academic tertiary care hospital and compared 45 women with a history of four or more failed IVF cycles (group A) with 44 apparently healthy women matched for age and ethnic origin (group B). All participants were tested for inherited thrombophilias: mutations of prothrombin, factor V Leiden and methylene tetrahydrofolate reductase (MTHFR), and protein C, protein S and antithrombin III deficiencies. RESULTS Excluding homozygotic MTHFR, the incidence of thrombophilia in group A, was 26.7% compared with 9.1% in group B (P = 0.003; odds ratio 2.9; 95% confidence interval 1.02-8.4). The incidence of thrombophilia in women with unexplained infertility in group A was 42.9% (9/21), compared with 18.2% in group B (P < 0.002). CONCLUSIONS These data suggest that inherited thrombophilia may play a role in the aetiology of repeated IVF failures, particularly in the subgroup with unexplained fertility.