Swedish authorities have cleared a birth control app known as “Natural Cycles” just two weeks after British authorities banned a company ad from Facebook.
The app at the center of the investigation was recently approved in the U.S. and relies on the “rhythm method” of birth control, which tracks women’s ovulation to determine which days of the month they are most likely to get pregnant.
The Swedish Medical Products Agency found that women who use the app correctly have only a 7 percent chance of getting pregnant, which is in line with what the company said it was. The conclusions are based on studies of more than 22,000 women between January and June of this year.
Raoul Scherwitzl, Natural Cycles CEO, said in a statement that he hoped the findings were reassuring to women.
“We never doubted the effectiveness of our product since the number of reported pregnancies is monitored closely on a monthly basis – this is an ongoing responsibility that we commit to as part of operating in a regulated environment,” he said.
The app was referred to Swedish authorities in January after a major hospital in Stockholm reported that 37 of the 668 women who had abortions there had been using Natural Cycles.
After its investigation, the Medical Products Agency asked the company to clarify the risk of unintended pregnancies, among other software changes, that Natural Cycles said it had already implemented earlier this year. The agency formally closed its investigation and did not ask for any other changes.
The latest announcement comes after the British Advertising Standards Agency announced Aug. 28 that it was banning a Natural Cycles ad that ran on Facebook claiming it was a “highly accurate” contraceptive method.
Natural Cycles is a 2014 startup developed by a married couple in Sweden, and in 2017, it became the first app to be certified as birth control in Europe. It reportedly has more than half a million subscribers across the world.
The app must be used precisely to work. It asks women to log their temperatures every single morning at roughly the same time using a basal body thermometer, a type that is more sensitive than a traditional thermometer.
Users then log their temperatures in the app. On “red” days, or “fertile days,” the app notifies women that they should not have sex without backup, such as a condom. On “green” days in the calendar, they are considered infertile and can proceed without additional protection.
In the U.S., clinical trials submitted to the FDA showed that women got pregnant 1.8 percent of the time when using the app correctly, but when the app was used incorrectly unintended pregnancies rose to 6.5 percent. Examples of using the app incorrectly include having unprotected sex on fertile days.