Inherited thrombophilia and obstetric complications

Inherited thrombophilia can be detected in at least 40% of patients with venous thromboembolism. More recently, inherited thrombophilia has been reported to be associated with an increased risk for obstetric complications, including fetal loss, preeclampsia, intrauterine growth restriction (IUGR) , abruptio placentae, those latter likely due to inadequate placental perfusion. The estimate of risk largely depends on the type of thrombophilic trait analyzed and on the criteria applied for the selection of the patients, producing in some cases contradictory results. Convincing evidence is available that deficiency of antithrombin (AT), protein C (PC), or protein S (PS), is a risk factor for late fetal loss. Factor V Leiden and prothrombin G20210A are associated with a doubled risk for unexplained recurrent early fetal loss and for non-recurrent late fetal loss. The association of inherited thrombophilia with preeclampsia is much more uncertain, being perhaps restricted to factor V Leiden and to more severe cases. Less data are available for IUGR and abruptio placentae. Treatment with s.c. low-molecular weight heparin for preventing recurrence of fetal loss among women with thombophilia is under investigation.