The obstetric complications in women with hereditary thrombophilia
All congenital thrombophilias are associated with an increased risk of venous thromboembolism (VTE) during pregnancy. Several studies have confirmed the increased risk of obstetric complications in women with congenital thrombophilias. Case-control, cohort and transversal studies have shown that hereditary thrombophilia is more prevalent in the cohorts of women with pregnancy losses, early onset preeclampsia, abruptio placentae and IUGR. However, despite the increase in the relative risk, the absolute risk of VTE and adverse pregnancy outcomes is low. There is convincing evidence that the deficiency of natural anticoagulants (AT, protein C, protein S) is a risk factor for late fetal loss. The mutations of the FVL (G1691A) gene and the prothrombin (G20210A) gene are associated with a double risk for unexplained RPL and non-recurrent late fetal loss. The association of congenital thrombophilia and preeclampsia is much more uncertain, being, probably, limited to the FVL G1691A gene mutation and more severe cases of preeclampsia. Fewer data are available for IUGR and abruptio placentae. In addition, genetic and epidemiological research suggest that obstetric complications during pregnancy have a polygenic multifactorial etiology, with a risk determined by the interaction of multiple genetic variants and other risk factors.