Oral contraceptives, hormone therapy and cardiovascular risk

Soon after combined estrogen/progestogen oral contraceptives (COCs) were introduced in the 1950s, it was established that they cause venous thromboembolism (VTE), that the risk is related to estrogen dose, and that COCs also increase the risk of myocardial infarction among female smokers over age 35. Stroke risk is also increased. early studies of supplemental hormone therapy were inconclusive.

To consider new findings. NEW FINDINGS ON ORAL CONTRACEPTIVES: Genetic predisposition to VTE has been established with the discovery of Leiden factor V mutation. Based on an irrational classification of low-estrogen-dose (

It is likely that the WHI studies were biased and that they overestimated the overall and time- and duration-specific risks of VTE, myocardial infarction and stroke. Particularly for myocardial infarction, a protective effect, perhaps strongest among the youngest women, but present at all ages, may correctly have been identified in earlier observational studies, and have been missed in the WHI studies. This paper was presented by Professor Shapiro as a Plenary Lecture at the 12th World Congress on Menopause, Madrid, May 2008.