Prevalence of thrombophilia in women with severe ovarian hyperstimulation syndrome and cost-effectiveness of screening.

OBJECTIVE: To determine the prevalence of markers of thrombophilia in patients with severe ovarian hyperstimulation syndrome (OHSS) and to evaluate the cost-effectiveness of screening for factor V Leiden and prothrombin G20210A mutations in women entering an IVF program. DESIGN: Case-control study and cost-effectiveness analysis. SETTING: University teaching hospital. PATIENT(S): Women undergoing controlled ovarian hyperstimulation for IVF complicated by severe OHSS (group 1, n = 20), women undergoing controlled ovarian hyperstimulation for IVF without development of severe OHSS (group 2, n = 40), and healthy control subjects (group 3, n = 100). INTERVENTION(S): Investigation of markers of thrombophilia. Estimate of number of IVF patients needed to detect a case of severe OHSS and thrombosis associated with thrombophilia genetic mutation was calculated from the available data. MAIN OUTCOME MEASURE(S): Blood samples were analyzed for inherited (resistance to activated protein C due to the factor V Leiden mutation; prothrombin G20210A mutation; deficiencies in antithrombin, protein C, and protein S) and acquired (presence of circulating lupus anticoagulants and/or anticardiolipin antibodies; deficiencies of antithrombin and protein S; acquired protein C resistance) markers of thrombophilia. The cost of preventing one thrombotic event in a patient developing severe OHSS after IVF and having factor V Leiden or prothrombin G20210A mutations was calculated. RESULT(S): None of the OHSS patients or controls had antithrombin, protein C, or free protein S deficiencies. All of them tested negative for antiphospholipid antibodies. No patient in group 1 had the factor V Leiden or prothrombin G20210A mutations. The prothrombin G20210A mutation was detected in 1 out of 40 patients (2.5%) in group 2. Both factor V Leiden and prothrombin G20210A mutations were detected in two of the control subjects (2%) (group 3). The estimated cost of preventing one thrombotic event arising as a consequence of screening for factor V Leiden and prothrombin G20210A mutation is a minimum of 418,970 dollars and 2,430,000 dollars, respectively. CONCLUSION(S): The prevalence of thrombophilia is not increased in women with severe OHSS. Screening for V Leiden and prothrombin G20210A mutation in an IVF general population is not cost-effective.