FDA approves marketing for pregnancy prevention app 'Natural Cycles'

The Food and Drug Administration has approved the marketing of the first smartphone app to prevent pregnancy.

The app, Natural Cycles, doesn't involve taking any medication. Instead the app contains an algorithm that calculates the days of the month the woman is likely to be fertile.

It does that by daily body temperature readings and menstrual cycle information.

A basal body thermometer is taken daily by women immediately when waking up in the morning. The reading is then entered into the app.

The agency said in a press release that 15,570 women who used the app for an average of eight months were involved in clinical studies that analyzed the effectiveness of the app.

The company behind the app says it has a 1.8 percent failure rate in its testing.