Natural Cycles, an app that purportedly tells women when they are fertile using an algorithm, is being blamed in Sweden for 37 cased of unwanted pregnancies because the algorithm screwed up, according to Swedish publication SVT.

Södersjukhuset hospital in Stockholm reported the app to Swedish regulator MPA (the Medical Product Agency) after those 37 women visited the hospital looking for an abortion as they had become pregnant while using the app. The app’s algorithm measures factors such as temperature and others to see when a woman may be fertile. Recently, the EU certified the app as a form of birth control, but that in of itself was fraught with a few risks.

Natural Cycles told The Verge that they are in touch with the MPA about the cases in question, though they haven’t heard anything specifically from the hospital in question.

“No contraception is 100% effective, and unwanted pregnancies is an unfortunate risk with any contraception. Natural Cycles has a Pearl Index of 7, which means it is 93% effective at typical use, which we also communicate.

At first sight, the numbers mentioned in the media are not surprising given the popularity of the app and in line with our efficacy rates. As our user base increases, so will the amount of unintended pregnancies coming from Natural Cycles app users, which is an inevitable reality.”

Cycles says that users under 18 should use another form of contraception instead of the app, which currently has 700,000 users worldwide. If you’d like to find your own date, check out UA Brides.

[The Verge]

About Matt Lichtenstadter

Recent Maryland graduate. I've written for many sites including World Soccer Talk,, Testudo Times, Yahoo's Puck Daddy Blog and more. Houndstooth is still cool, at least to me. Follow me @MattsMusings1 on Twitter, e-mail me about life and potential jobs at matthewaaron9 at Yahoo dot com.