Is Your Birth Control as Safe as You Think?
Since NuvaRing hit the market, more than 700 women have filed lawsuits, claiming it has caused potentially life-threatening blood clots. The battle may change the way millions of women prevent pregnancy.
Merck, hoping to avoid a similar fallout, is standing by its product. "The decision was made to use this particular form of progestin [in Nuva Ring] because of the long history of safety and efficacy," says Dr. Michelle Vichnin, one of Merck's medical directors. When contacted by Marie Claire regarding the pending lawsuits, a Merck spokesperson stated: "The company intends to defend itself against these lawsuits." Possibly helping their case: In March 2010, researchers from the Cochrane Collaboration, a respected international organization that reviews published scientific data, analyzed 10 randomized studies of NuvaRing involving 3,000 women. They found that only two women in the study group developed clots, and one was later found to have a genetic risk.
Often lost in the discussion is just how unlikely the average healthy woman's chances of getting a blood clot are, whether she takes a second- or third-generation birth control. The risk of blood clots for women on a desogestrel-based contraceptive is about 30 out of 100,000, according to some studies — still less than half a percent. You're more likely to get struck by lightning over the course of your lifetime. And that risk is still severalfold less than that of a woman who is pregnant or postpartum. Another issue undermining the claims against Merck is the scope of prior studies, which didn't look at a large enough pool of NuvaRing users, according to Dr. Andrew Kaunitz, a professor at the Department of Obstetrics & Gynecology at the University of Florida in Jacksonville. (Kaunitz consults for several pharmaceutical companies, including Merck.) To investigate the effect of something so marginal, he says, scientists need to conduct much bigger studies on women who do not have any known risk factors for clots. "When you're looking at rare events, even small biases can throw off your findings," says Kaunitz.
Larger studies are on the way. Merck is currently underwriting a massive trial of some 30,000 NuvaRing and pill users — the largest, most comprehensive study of the contraceptive to date. The company says it expects to publicize results next year. "The study was started because we wanted to answer questions that were being discussed in the medical community," says Merck's Vichnin. Meanwhile, all eyes are on the impending litigation against fourth-generation pills like Yaz and Yasmin, also under fire for their potential blood clot risks and set to go to trial in September.
So what should NuvaRing users do in the meantime? Don't be afraid to ask your doctor questions about which birth control is right for you, given your medical history and lifestyle. There are close to 100 oral and pill-free contraceptives on the market today, yet many women take whatever their gynecologist recommends, no questions asked. Says epidemiologist Rosendaal, "It's not like there aren't options."