The US Food and Drug Administration (FDA) has approved Sweden-based Natural Cycles, making it the first direct-to-consumer smartphone app used for digital contraception to be marketed in the country.
Natural Cycles is based upon the concept of fertility awareness and uses an algorithm to calculate the days in a month a woman is likely to be fertile based on daily body temperature and menstrual cycle information.
Consumers using the app must take their temperature daily using a basal body thermometer, which is accurate to two decimal points, and then input this information into the app. The system then informs the user if they need to use protection to prevent pregnancy that day. The app’s reliance on human input means there is a possibility of human failure or error.
The FDA’s decision was based clinical trials involving 15,570 participants who used the app for an average of eight months. Results from these studies showed the app was 93% effective with a so-called ‘perfect use’ failure rate of 1.8% and a ‘typical use’ failure rate of 6.5%.
The regulator did warn, however, that the app shouldn’t be used by women for whom pregnancy would present a major risk for the mother or foetus, or by women taking contraception or hormone treatments that inhibit ovulation.
FDA Center for Devices and Radiological Health assistant director for the health of women Terri Cornelison 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. But women should know that no form of contraception works perfectly, so an unplanned pregnancy could still result from correct usage of this device.”
Simultaneous with the marketing approval of Natural Cycles, the FDA created special controls to clarify the agency’s expectations in assuring the accuracy, reliability and effectiveness in preventing pregnancy using the app.
Natural Cycles received CE approval in early 2017, which means it is available in the European Union and general European Economic Area. In total it currently has approximately 900,000 registered users.
Natural Cycles chief technology officer and co-founder Elina Berglund said: “Based on the strength of our clinical data, Natural Cycles is the only app to be CE marked in Europe as a method of contraception, and we are delighted that the FDA has now granted the De Novo for Natural Cycles in the US.
“Our mission at Natural Cycles is to pioneer women’s health with research and passion, and we hope that by increasing the options available, more women will be able to find a method of contraceptive that works for them.”
The system has begun to face some criticism in recent months. Its certification is currently under review in Sweden after a hospital reported that 37 of the 668 women who sought an abortion between September and December 2017 were using the app as their sole method of birth control.