In October 2013, Jürgen Dinger, Sabine Möhner, and Klaas Heinemann published the article “Cardiovascular Risk Associated With the Use of an Etonogestrel-Containing Vaginal Ring,” hereafter “Cardiovascular Risk,” in the journal Obstetrics and Gynecology. The authors enrolled patients in the study who were new users of either a vaginal contraceptive ring known as NuvaRing or a combined oral contraceptive pill. A combined oral contraceptive pill contains a formulation of the hormones progesterone and estrogen. They followed up with the patients for two to four years after they had started either hormonal contraceptive treatment to record the incidence of specific cardiovascular events. The authors found that the risks of cardiovascular events when starting use of either NuvaRing or a combined hormonal contraceptive pill were similar to each other in the patients they studied. The results of “Cardiovascular Risk” affirmed the results of similar studies and stated that the risk of cardiovascular events was similar in NuvaRing users to other contraceptive users.

In 2012, Stephen Sidney, T. Craig Cheetham, Frederick A. Connell, and colleagues published “Recent Combined Hormonal Contraceptives (CHCs) and the Risk of Thromboembolism and Other Cardiovascular Events in New Users,” hereafter “Combined Hormonal Contraceptives” in Contraception. The authors gathered records of major cardiovascular events in patients who were using combined hormonal contraceptive treatments, or CHCs. A CHC is a birth control medication that contains both estrogen and progestin hormones. The CHCs of focus, which the authors referred to as the study CHCs, included a pill, patch, and vaginal ring that the US Food and Drug Administration, or FDA, recently approved at the time of publication. The researchers compared the rates of cardiovascular events between users of the study CHCs to users of established CHCs to find any increased cardiovascular risk. “Combined Hormonal Contraceptives” showed that the study CHCs did come with some increased cardiovascular risk, and reconfirmed the known cardiovascular risks of CHCs in general, providing safety information for people who may want to start birth control.