Vanity Fairwriter-at-large Marie Brenner investigates the birth-control device NuvaRing, which has allegedly caused blood clots in thousands of its users. As NuvaRing’s manufacturer, Merck, which made $623 million in NuvaRing sales in 2012, is facing roughly 3,500 lawsuits against it, Brenner asks why, despite evidence of serious risk, this potentially lethal contraceptive remains on the market. Would a young woman use NuvaRing, Brenner asks, if she knew that the F.D.A. had determined that there was a 56 percent increased risk of blood clots when it was compared with birth-control pills using earlier forms of progestin? Karen Langhart, the mother of Erika Langhart, a 24-year-old who died of a pulmonary embolism on Thanksgiving Day 2011 after using NuvaRing for approximately four years, tells Brenner, “I want to warn every mother and every daughter: do not use the product that killed my child.”

Brenner tells the story of Erika Langhart, whose boyfriend came home the Monday before Thanksgiving to find her writhing on the floor, struggling for air. Erika was rushed to the hospital and placed on life support. Karen recalls speaking on the phone to a doctor in the emergency room, who asked, “Was your daughter using birth control?” After Karen told him that Erika had been using NuvaRing, he said, “I thought so, because she’s having a pulmonary embolism.” On the program for her daughter’s memorial service, Karen stated, “Cause of Passing: Massive, Double Pulmonary Embolism—a direct result of the NuvaRing.” Karen tells Brenner that she had entered “another phase of life. How I wish I could change places with my daughter. I am living every parent’s nightmare.”

Brenner also speaks to Megan Henry, coincidentally a college classmate of Erika’s and a member of World Class Athletes, the army’s elite team of soldier-athletes. Ten days after she had started using NuvaRing, Megan, like Erika, found herself gasping for breath. “One doctor I went to told me I was under stress, or maybe I had asthma,” she tells Brenner. “He gave me an inhaler.” On a flight to Florida for more training, she almost collapsed. “At Urgent Care, I was given an X-ray—it was clear. I said, ‘Could this be the Nuva­Ring?’ ‘Absolutely not,’ the doctor said.” Megan’s mother, Barbara, told her, “Megan, you need to come home now, and I will get you an appointment with a pulmonologist.” After a second flight—she later learned that that alone could have killed her—Megan told her history to a Connecticut doctor, who ordered a CT scan. It revealed dozens of blood clots in her lungs. Rushed to the hospital, she was put on blood thinners in the E.R., and she remained hospitalized for a week. “I was told, ‘Your career as an athlete is over,’ ” she said. “If you weren’t in the shape you are, you would be dead,” her doctor informed her. Though Megan tells Brenner that she is almost back to normal and training again, she will have a much higher risk of blood clots for the rest of her life, she said, and if she gets pregnant, she will likely have to go on a painful regimen of injections of Lovenox to prevent clots.

Brenner interviews Hunter Shkolnik, a lawyer bringing lawsuits against Merck. Shkolnik tells Brenner that Organon (the Dutch pharmaceutical company that created the device) launched into NuvaRing’s marketing with a scientist’s research study that had examined only 16 women using NuvaRing. That study, No. 34218, on the release of hormones in different birth-control delivery systems, was so outrageous, Shkolnik tells Brenner, that he felt it justified focusing his entire legal career on drug cases. Shkolnik tells Brenner that the summary prepared by Organon for the F.D.A. was attached to thousands of pages of backup, in which were buried the risks associated with blood clots. “This is a standard subterfuge used by Pharma,” he says. “You bury your bad news in one of 500 studies you have done on ease of use or lipid disorder. Then when the F.D.A. comes back to the drug company, the drug company can say, ‘You had it in your documents.’ If it isn’t in the 30-page summary, the F.D.A. is so understaffed it will never be noticed.”