Thrombophilia in women undergoing medically assisted reproduction – prevalence and clinical consequence

In Denmark, 10 % of new-borns are being conceived with the aid of medically assisted reproduction (MAR). MAR can imply induction of high levels of oestradiol, which in turn leads to increased coagulation activity, decreased natural anticoagulant activity, and reduced fibrinolytic activity. Venous thromboembolism (VTE) is therefore a feared complication, especially in women with other risk factors for VTE, such as family history of VTE, previous VTE, or thrombophilia. Thrombophilia screening is advised in women with clinical risk factors of VTE prior to undergoing MAR. Women with thrombophilia should be handled according to current thrombosis prophylaxis guidelines. The aim of this study was to investigate the prevalence of thrombophilia in women undergoing MAR compared to the general population, to get an overview of the clinical consequences for women with thrombophilia, and to ensure that the national recommendations regarding thrombophilia screening, are being complied with. A total of 160 women referred from three public fertility clinics, from 1 May 2015 to 1 May 2020, for thrombophilia investigation prior to MAR, were included. Thrombophilia analyses included both the genetic factors and acquired factors. A higher prevalence of heterozygous factor V Leiden (14 %) and protein S deficiency (2 %) was found in our study population as compared with the general Western population. We found a higher prevalence of some thrombophilias in women referred to MAR. • Many newborns are conceived by the aid of medically assisted reproduction (MAR). • MAR, with high levels of oestradiol, increases the risk of venous thromboembolism. • Thrombophilia screening is advised in some women prior to MAR. • A higher prevalence of some thrombophilias was found in women referred to MAR.