Hormonal Contraceptives and Arterial Thrombosis — Not Risk-free but Safe Enough

The link between combined estrogen–progestin oral contraceptives and venous and arterial thrombosis was made soon after these products were marketed, in the early 1960s.13 By 1970, the doses of estrogen in combined estrogen–progestin oral contraceptives had already been lowered on the basis of epidemiologic data showing that formulations with higher estrogen doses were associated with increased vascular risks.4 Studies published in 1995 and 1996 showed that increases in the risk of venous thromboembolism were greater with newly marketed estrogen–progestin oral-contraceptive formulations containing desogestrel and gestodene than with formulations containing levonorgestrel and other “older” progestins.58 Much attention has since . . .