
Women taking the most recent entries into the hormonal contraception market are putting themselves at higher risk for potentially lethal blood clots. At the same time, women taking older birth control pills run a greater risk for developing the chronic immune system disease lupus.
Two studies posted to the BMJ Web site this week highlight the increased clotting risk for women taking birth control pills that contain any male hormone other than levonorgestrel or norgestrel. Dutch researchers found that women's risks for deep vein thrombosis was highest when they used pills containing desogestrel (e.g., Cyclessa from Organon) and drosperinone (e.g., Yaz from Bayer Healthcare). Danish researchers corroborated this finding.
Ojvind Lidegaard, who served as lead author for the Danish study report, told Health Day that "the fourth-generation pills are not safer than the first-generation pills, which we had not expected."
Announcement of the increased clotting risks for newer, higher-dose oral contraceptives comes a few months after British researchers published data in the journal Arthritis Care & Research showing that birth control pills containing the highest doses of estrogen raised women's risk for developing lupus. First-generation birth control pills such as Warner Chilcott's Ovcon contain doses of estrogen as high as 50 micrograms. Fourth-generation pills such as Yaz contain just 20 micrograms of estrogen.
The take-home message for women and their doctors from these conflicting research findings comes from an editorial Nick Dunn wrote to accompany the BMJ articles on the Dutch and Danish studies: "All oral contraceptives are effective in preventing pregnancy if they are taken correctly, so the choice of which one to use rests on the profile of side effects."