A number of oral contraceptives have recently been under intense scrutiny for their link to dangerous and potentially fatal blood clots, but now scientists are studying the effects of various forms of birth control, and have found these measures also have an increased risk for serious blood clots.
According to HealthDay, the Danish study found that alternative contraceptives, such as skin patches, implants and vaginal rings, may be more dangerous than pills. Researchers suggested that women using these forms of birth control may want to switch to the pill.
According to the National Library of Medicine, a blood clot, or deep venous thrombosis, most commonly forms in the legs, where it can produce swelling and soreness. However, if the clot breaks free and travels through the blood to the lungs, known as a pulmonary embolism, the result can be deadly.
"The transdermal patch and vaginal ring confer at least a sixfold increased risk of venous thrombosis as combined pills with desogestrel or drospirenone, a risk which is about twice the risk among women using second-generation pills with levonorgestrel," said lead researcher Dr. Ojvind Lidegaard, an Ob/Gyn professor at the University of Copenhagen.
However, Lidegaard added that hormone-releasing intrauterine devices (IUDs) were not included in the list of potentially dangerous birth control alternatives.
"Women should be informed about these risks in order to be able to choose the most appropriate hormonal contraceptive product," he said. "There are hormonal contraceptive alternatives which confer less or no risk of venous thrombosis."
In the study, the team of researchers analyzed data on venous thrombosis incidents in Denmark on women who were using birth control other than the pill. The women's ages ranged from 15 to 49. The findings, which were published in a may issue of the British Medical Journal, showed that between 2000 and 2010, more than 3,400 women were diagnosed with venous thrombosis. Among women who did not take any hormonal contraceptive, two women developed the condition for every 10,000 combined years contraceptives were used.
Women using the oral contraceptive levonorgestrel showed a blood clot risk that was three times higher than those who did not take any contraceptive, with 6.2 clots for every 10,000 combined years the pill was taken. Among those who used a skin patch, the risk grew to about eight times higher, or 9.7 clots per 10,000 years. Women using a vaginal ring showed a 6.5 times higher risk for developing blood clots.
"For the majority of young women, the recommendation is second-generation combined pill with levonorgestrel, and for women who have given birth, that a hormone-releasing intrauterine device is an attractive option, because it at the same time does not increase the risk of venous thrombosis, perhaps even protects against them, and reduces menstrual complaints," Lidegaard said.
The authors concluded that more women should switch from using alternative forms of birth control to oral contraceptives, which the study suggested were less risky.
Dr. Elizabeth Poynor, a gynecologist at Lenox Hill Hospital in New York City, stated that many forms of birth control have appeared in the last few years, giving rise to more use, and in turn, more reports of blood clots.
"While these types of transdermal hormonal contraceptives may be more convenient for some women and lead to better compliance with appropriate use, they have their own set of medical side effects and concerns," she said."This highlights the importance of reviewing the risks, benefits and alternatives among differing types of medications within the same broad category."