Natural Cycles requires women enter a daily basal thermometer body temperature to detect minor rises in temperature at the time of ovulation. It also tracks the user’s menstrual cycle.
The US Food and Drug Administration (FDA) has granted marketing to the first mobile medical app designed as a method of pregnancy contraception.
Natural Cycles, a mobile app that contains an algorithm which calculates the days of the month a women is most likely to be fertile, is intended for fertility awareness contraception use in pre-menopausal women aged 18 years and older.
The service requires women enter a daily basal thermometer body temperature in the early morning, as basal thermometers are more capable of detecting minor rises in temperature at the time of ovulation. The app also tracks the user’s menstrual cycle. When the user is most fertile—generally 4-5 days per month—the app alerts the user and recommends contraception or abstinence.
A series of clinical trials to evaluate the app’s efficacy tested its use in 15,570 women over an average of 8 months. According to the investigators, the app scored a “perfect use” failure rate of 1.8%, meaning 1.8 in every 100 women who use the app annually will because they had sexual intercourse on a day when the app predicted less fertility or because their contraceptive method failed during sexual intercourse on fertile day.
The app also had a “typical use” failure rate of 6.5%, in instances where women incorrectly used the app.
The novel marketing approval comes at an age of burgeoning telehealth measures, though the FDA reiterates that consumer-friendly devices such as Natural Cycles require caution.
“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,” Terri Cornelison, MD, PhD, assistant director for the health of women in the FDA’s Center for Devices and Radiological Health, said in a statement. “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 had previously reviewed Natural Cycles through its De Novo premarket regulatoy review pathway, indicating its purpose as a novel, low-to-moderate-risk device of a new type.
Natural Cycles Nordic AB, the marketing company behind the app, advised that women who have a medical condition where pregnancy would be associated with a significant risk to the mother or the fetus or those currently using birth control or hormonal treatments that inhibit ovulation should not use the app.