Canadian women are sounding the alarm about the NuvaRing birth-control device after a major U.S. magazine linked the vaginal ring to blood-clot-related fatalities, but the head of a group representing Canada's obstetricians and gynecologists says the dangers are overblown.
Jennifer White, a 26-year-old communications specialist in Ottawa, said she alerted her Facebook and Twitter networks on Monday as soon as she read the online version of the article in the January edition of Vanity Fair, which questioned why the NuvaRing contraceptive remains on the market despite evidence of serious risk.
White stopped using the NuvaRing five weeks ago after her migraines worsened to the point that she sometimes lost her vision. Her doctor attributed the migraines to changes in blood flow due to hormonal contraception, and ordered her to stop using the NuvaRing, White said. The Vanity Fair article has raised fears among her peer group, she said, because the relative risk of adverse effects with the NuvaRing compared with other hormonal contraceptives is uncertain. "It's terrifying," she said.
Approved by Health Canada in 2002, the NuvaRing is a bendable plastic loop that releases ovulation-suppressing hormones into the vagina for three weeks until it is removed for a menstrual period. The device has been promoted as a carefree alternative to birth-control pills and the lowest-dose hormonal contraceptive on the market. But Merck, the NuvaRing's manufacturer, faces roughly 3,500 lawsuits related to the product, including a major class-action suit due to appear in U.S. federal court in January. Plaintiffs allege they suffered serious adverse effects, including deep vein thrombosis, a blood clot in a deep vein that can travel to the lungs, causing organ damage and death.
Concerns about the NuvaRing rest largely on two studies. In 2011, the U.S. Food and Drug Administration found that women using the vaginal ring had a 56-per-cent increased risk of blood clots compared with those on contraceptives using an older form of estrogen. In 2012, a Danish study published in the British Medical Journal found that women who used the vaginal ring were at least six times more likely to develop deep vein thrombosis than women who did not use hormonal contraceptives.
The studies suggest the NuvaRing may carry the risk of a third-generation hormonal product, a class that includes the controversial Yaz and Yasmin birth-control pills that have cost manufacturer Bayer more than a billion dollars in out-of-court settlements.
Neither study is conclusive, however, since the women were not randomly selected and did not use hormonal contraceptives for the same lengths of time, said Dr. Jennifer Blake, chief executive officer for the Society of Obstetricians and Gynaecologists of Canada. The majority of adverse events from hormonal contraception occur within the first few months of use, she explained.
Moreover, the alarming reports do not put the actual risks in context, she added.
The risk of blood clots from hormonal contraceptives varies from 1 to 2 women in 10,000 to 4 to 6 in 10,000. When the number of adverse events is this small, it only takes 2 to 4 women with deep vein thrombosis for a study to report a twofold increased risk, Blake explained. "It's easy to make a number seem very scary," she said, "but this is still all within the range of safe."
Health Canada's database of adverse reactions, based on voluntary reports, lists 110 serious events linked to the NuvaRing as of June 30, 2013, including deep vein thrombosis, depression and unintended pregnancy.
All contraceptives carry risks, Blake pointed out. So does pregnancy: 1 to 3 in 1,000 pregnant women will experience a blood clot, she said.
Women taking hormonal contraceptives are at greater risk for blood clots if they are smokers, obese, sedentary or over age 35. Women with these risk factors should consider using second-generation hormonal contraceptives that carry a slightly lower risk of blood clots, she said.
As for women who have used the NuvaRing for some time without adverse effects, the recent reports about the vaginal ring "really need not concern them," Blake said.