Public health agency the US Food and Drug Administration (FDA) announced on Friday that it has approved the marketing of the first mobile medical application, called Natural Cycles, which can be used as a method of contraception to prevent pregnancy.

The FDA awarded marketing authorisation for this app to Natural Cycles Nordic AB through the de novo premarket review pathway.

According to the FDA, Natural Cycles contains an algorithm that calculates the days of the month a woman is likely to be fertile based on daily body temperature readings and menstrual cycle information, a method of contraception called fertility awareness.

Designed for mobile devices, The Natural Cycles is intended for use in pre-menopausal women aged 18 and older, the FDA added.

Natural Cycles requires women to take their temperature daily using a basal body thermometer immediately upon waking in the morning, then enter the reading into the app, track a user's menstrual cycle as well as should abstain from sex or use protection when they see "fertile day" displayed on the app, which is four or five days a month.

Clinical studies to evaluate the effectiveness of Natural Cycles for use in contraception involved 15,570 women, who used the app for an average of eight months. The app had a "perfect use" failure rate of 1.8% and a "typical use" failure rate of 6.5%.