Summary: Birth control pills (like Yaz and Yasmine) containing drospirenone may increase the risk of blood clots in women.

Studies show that there is an increased risk for venous thrombosis and pulmonary embolism in women who regularly use oral contraceptives containing drospirenone.
 

• A recent study consisting of 330,000 Israeli women reportedly found that women who regularly use birth control pills made with a hormone called drospirenone (typically found in brands like Yaz and Yasmine) are more likely than other birth control pill users to develop a condition called venous thromboembolism (VTE). Women with VTE develop blood clots that start in the leg veins and can travel to the lungs, where the clots can cause pulmonary embolism (PE). According to this study, there were 1017 women out of the 330,000 women (around 6 events per 10,000 women per year) who developed thrombotic events during the study period. In a multivariable model, they found that women using birth control using drospirenone were at an increased risk for these blood clot diseases (VTE and PE). Various recent studies, including this one, show the possibility of the risk being much higher with birth control pills containing drospirenone. There are several other factors that can increase the chances for venous thromboembolism such as older age, obesity, smoking, and/or high blood pressure. For this reason, it is important for women to talk to their doctors about their risk factors and to avoid birth control pills with the highest blood clot risk.¹

¹Higher risk of venous thrombosis associated with drospirenone-containing oral contraceptives: a population-based cohort study, Canadian Medical Association, 2011, pp. 1-7.