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.

The NuvaRing is a self-administered hormonal contraceptive device in the form of a flexible plastic ring that is inserted into the vagina. It releases the hormones etonogestrel and ethinylestradiol, which are synthetic forms of the female reproductive hormones progesterone and estrogen, respectively. The pharmaceutical company Organon first made NuvaRing in the Netherlands in 1980s. The Netherlands first approved it for use in February of 2001, and the United States did the same in October of that year. To insert the NuvaRing, a user pinches the ring together to compress it and inserts it into the vaginal canal, where its exact placement does not matter. The NuvaRing stays in the vagina for three weeks, after which the user removes it for one week. During the week following removal, the user experiences bleeding similar to a menstrual period. The NuvaRing was one of the first monthly vaginal rings used for contraception, and it provides a self-administered method of birth control, which can be more accessible for some users than taking a birth control pill every day.

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.