Hormone Therapy and Risk for Venous Thromboembolism

Observational studies and randomized controlled trials have shown consistently that oral hormone therapy raises risk for venous thromboembolism (VTE) in postmenopausal women. In this systematic review, investigators sought to estimate risk for VTE among users of hormone therapy, taking into account study design and treatment characteristics (e.g., route of administration, type of estrogen, treatment duration).

In analysis of data from eight observational studies, the pooled odds ratio for first VTE in current oral estrogen users, compared with nonusers, was 2.5. Risk for VTE was similarly higher among users of oral estrogen alone and users of estrogen plus progesterone versus nonusers. Risk for VTE was highest during the first year of oral e…