In a first, the Food and Drug Administration said Friday it will let a Swedish company market a mobile application that can be used as a form of contraception.
Dubbed “Natural Cycles,” the smartphone app calculates when a woman is likely to be fertile by using daily temperature readings and menstrual cycle information.
Women who want to rely on the app must take their temperature upon waking each day and enter the reading into the app.
The FDA said women much use a basal thermometer, which is more sensitive than regular thermometers to slight changes in temperature at ovulation.
Users should avoid sex on days the app reads “fertile day,” or use another form of contraception on those days, which will typically occur four or five times a month, the agency said.
“Consumers are increasingly using digital health technologies to inform their everyday health decisions, and this new app can provide an effective method of contraception if it’s used carefully and correctly,” said Terri Cornelison, assistant director for women’s health at the FDA’s Center for Devices and Radiological Health. “But women should know that no form of contraception works perfectly, so an unplanned pregnancy could still result from correct usage of this device.”
The FDA said Natural Cycles had 1.8-percent failure rate among women who used it perfectly in clinical studies involving 15,570 women, meaning 1.8 in 100 users will become pregnant by having sexual intercourse on a day when the app claimed they were not fertile, or because another contraception method failed on a day when the app said they would be fertile.
It had a “typical use” failure rate of 6.5 per 100, which accounted for women not using the app correctly at all times or having unprotected sex on fertile days.
On Twitter, the maker of Natural Cycles said it was “delighted” that federal regulators had cleared its product as “the first digital method of birth control in the U.S.”
“This decision enables us to commercialize in the United States as a key step in our global strategy,” company co-founder Elina Berglund said.
The company says its product is best for women aged 20 to 40 who are comfortable using condoms on their fertility days.
“Hormonal contraception affects your cycle and temperature, so you cannot start using Natural Cycles until you have come off it,” its website says.