Fresh evidence confirms links between newer contraceptive pills and higher risk of venous thromboembolism

In this week’s issue of The BMJ, Vinogradova and colleagues (doi:10.1136/bmj.h2135) report the results of a large study on the effects of combined oral contraceptives on the risk of venous thromboembolism, conducted in two large United Kingdom databases: the Clinical Practice Research Datalink (CPRD) and QResearch. The authors identified over 10 500 cases of VTE in women aged 15-49 years and around 42 000 matched controls to address the inconsistencies and limitations of earlier studies. Older oral contraceptives (those containing levonorgestrel or norethisterone) showed results consistent with previously published findings: current users of oral contraceptives are at increased risk of venous thromboembolism compared with non-users of similar age and health status. Relative to non-users, risks were increased by around 2.5-fold for users of older oral contraceptives.

Notably, Vinogradova and colleagues also looked at the newer oral contraceptives, such as those containing desogestrel, gestodene, and cyproterone, as well as the newest pill containing drospirenone, where data have been limited and the magnitude of effects on the risks of venous thromboembolism remains controversial. They found that the newer contraceptives increased …