The International Thrombosis and Haemostasis Society (ISTH) has launched the first international observational-observational study WiTEAM 2018-2020 (Women International Team) to determine the cause-effect relationship between genetic thrombophilia and reproductive problems in women: infertility, abortions of repetition, fetal death and preeclampsia. The coordinator of this study is Dr. Amparo Santamaría, member of the Haemostasis and Thrombosis Unit of the Vall d'Hebron University Hospital and researcher of the http://en.vhir.org/portal1/grup-equip.asp?s=recerca&contentid=186733 Experimental Hematology Group of the Vall d'Hebron Research Institute (VHIR).Thrombosis is the leading cause of death in women during pregnancy, mainly as a consequence of pulmonary embolism, according to a previous study called TEAM (Thrombosis in the Scope of Women), also led by Dr. Santamaría and by the Society Spanish Thrombosis and Hemostasis. According to this study, 10% of pregnant women have some thromboembolic complication during pregnancy or the puerperium, In vitro fertilization or hormonal treatments increase the risk of thrombosis up to 10 times more than a natural pregnancy. In addition, 41% of women who have some type of thrombophilia suffer a thromboembolic event during pregnancy or puerperium. As a result of this study, Dr. Santamaría explains, "a much more ambitious study has been launched: the WiTEAM 2018-2020". The WiTEAM 2018-2020 study, led by Dr. Santamaría, "will focus on monitoring a group of 3,000 women from different countries who are carriers of a genetic thrombophilia with a dual objective: to establish a therapeutic protocol to prevent thrombosis during pregnancy and prevent infertility or problems of placental insufficiency that prevent pregnancy or that it comes to term. " The study will be carried out in more than 30 countries around the world.Fertility problems and genetic thrombophiliaOne in four patients with fertility problems or serious complications during pregnancy carries a genetic thrombophilia caused by Factor V Leiden deficiency, the mutation of the prothrombin gene, the factor XII mutation, the ABO blood group or Factor VIII levels. Other prothrombotic risk factors and, therefore, should be evaluated in each case are, above all, family genetic inheritance, that is, having relatives with a history of thrombosis and also other risk factors such as obesity, diabetes, age (having more 35 years old) and having suffered a previous thrombotic episode.In this sense, Dr. Santamaría believes that "the study is an opportunity for haematologists, obstetricians, gynecologists and specialists in assisted reproduction to join efforts in both diagnosis and preventive treatment to establish guidelines and consensus."