Estrogen receptor 1 haplotype does not regulate oral contraceptive-induced changes in haemostasis and inflammation risk factors for venous and arterial thrombosis.

Background: Administration of oral contraceptives (OCs) has profound effects on the plasma levels of haemostasis and inflammation variables, resulting in an increased thrombosis risk. Individuals show large differences in the response of these variables to OCs. Polymorphism in the estrogen receptor-1 (ER1) gene may explain part of this inter-individual response.