Oral contraceptives and thromboembolic disease: effects of lowering oestrogen content

The introduction of low-oestrogen oral contraceptives in Sweden and the concomitant disappearance of high-dose preparations did not result in a lowering of the mortality of fertile women from thromboembolic disease. Morbidity due to thromboembolism seems to have fallen, and the number of thromboembolic incidents reported to the Swedish Adverse Drug Reaction Committee decreased dramatically. The decrease was due exclusively to a reduction in venous thromboembolic disease: the frequency of arterial complications (cerebral and coronary) remained constant.