Venous thromboembolism in women: a specific reproductive health risk

BACKGROUND Venous thromboembolism (VTE) is a specific reproductive health risk for women. METHODS Searches were performed in Medline and other databases. The selection criteria were high-quality studies and studies relevant to clinical reproductive medicine. Summaries were presented and discussed by the European Society of Human Reproduction and Embryology Workshop Group. RESULTS VTE is a multifactorial disease with a baseline annual incidence around 50 per 100 000 at 25 years and 120 per 100 000 at age 50. Its major complication is pulmonary embolism, causing death in 1-2% of patients. Higher VTE risk is associated with an inherited thrombophilia in men and women. Changes in the coagulation system and in the risk of clinical VTE in women also occur during pregnancy, with the use of reproductive hormones and as a consequence of ovarian stimulation when hyperstimulation syndrome and conception occur together. In pregnancy, the risk of VTE is increased ~5-fold, while the use of combined hormonal contraception (CHC) doubles the risk and this relative risk is higher with the more recent pills containing desogestrel, gestodene and drospirenone when compared with those with levonorgestrel. Similarly, hormone replacement therapy (HRT) increases the VTE risk 2- to 4-fold. There is a synergistic effect between thrombophilia and the various reproductive risks. Prevention of VTE during pregnancy should be offered to women with specific risk factors. In women who are at high risk, CHC and HRT should be avoided. CONCLUSIONS Clinicians managing pregnancy or treating women for infertility or prescribing CHC and HRT should be aware of the increased risks of VTE and the need to take a careful medical history to identify additional co-existing risks, and should be able to diagnose VTE and know how to approach its prevention.