According to a study published on October 25 in The British Medical Journal, newer-generation birth control pills, specifically those containing the progestogen hormones drospirenone, desogestrel or gestodene, double the risk for venous thromboembolism (VTE), compared to older-generation contraceptives containing the progestogen hormone, levonorgestrel. Best-selling brands and generics like Yaz and Ocella are examples of the types of birth control pills currently under intense scrutiny by the U.S. Food and Drug Administration, as well as other regulatory agencies and watchdog groups.

Led by Dr. Ojvind Lidegaard of the University of Copenhagen, the study included approximately 1.2 million non-pregnant women, between the ages of 15 and 49, all of whom had no previous history of thrombotic disease. Its results revealed that women taking older-generation birth control pills were at three times the risk for developing VTE, compared to those not taking any hormonal contraceptive. Alarmingly, however, women taking drospirenone-containing birth control pills were at six to seven times the risk for VTE compared to non-users. The results undeniably undoubtedly confirm that women taking newer-generation birth control pills are at a significantly higher risk for developing potentially serious and even life-threatening blood clots.

VTE is a blood clot that forms deep within a leg vein, and can be especially dangerous (even deadly) if the clot travels to the heart, brain or lungs. Women taking a drospirenone-containing birth control pills, should be aware of the warning signs of VTE, which include continuous and severe leg pain, severe chest pain or shortness of breath.