Low dose oestrogen combined oral contraception and risk of pulmonary embolism, stroke, and myocardial infarction in five million French women: cohort study

This study (n=5,443,916) found that for the same dose of oestrogen, desogestrel and gestodene were associated with statistically significantly higher risks of pulmonary embolism but not arterial thromboembolism compared with levonorgestrel.

The authors also found that for the same type of progestogen, an oestrogen dose of 20 µg versus 30-40 µg was associated with lower risks of pulmonary embolism, ischaemic stroke, and myocardial infarction.

An editorial discusses the implications of this research.  It suggests that, assuming all other considerations are equal, levonorgestrel-containing pills should be the first choice when prescribing a combined oral contraceptive. Whatever progestogen is used, combinations with the lowest oestrogen dose should be selected to minimise the overall cardiovascular risk.