HRT and the risk of deep vein thrombosis

Venous thromboembolism (VTE) has long been recognized as a risk of oral contraceptive use in women, but until recently hormone replacement therapy (HRT) was not thought to be associated with a similar risk; the epidemiological literature having been reassuring. The recent publication of four independent epidemiological studies has changed our perspective on VTE risk on HRT. These studies suggest that the risk of VTE may be increased by up to three-fold during HRT. However, the absolute risk remains low at approximately one occurrence in 5000 woman-years and appears greatest in the early years of HRT use. However, given that mortality from VTE is low, it seems unlikely that these new findings will substantially change the overall balance of benefits and risks associated with long-term HRT. (C) 1997 International Federation of Gynecology and Obstetrics.