There are a lot of birth control options out there: pills, rings, patches, IUDs, diaphragms — even the withdrawal method. Not every type works for every person or relationship, and some people opt for more of a “natural family planning” route by keeping track of the cycles of the person with the uterus and avoiding having intercourse during the most fertile period.
But it turns out, relying solely on an app that tracks fertility may not be enough. Recently, 37 women have reportedly gotten pregnant unintentionally while using the Natural Cycles app, which has been a European Union-certified form of contraception since August 2017.
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And there may be more unplanned pregnancies than the 37. The Verge reports that Södersjukhuset hospital in Stockholm alerted Swedish regulator MPA (the medical product agency) about the failings of Natural Cycles after 37 women visited the hospital for an abortion after becoming pregnant while using the app. In other words, additional people may have become pregnant but didn’t visit this particular hospital to get an abortion (or end the pregnancy at all).
Natural Cycles works similarly to other fertility-tracking apps, using an algorithm to measure different bodily signals like temperature, ovulation and sperm survival rates to predict when the user is most (and least) fertile. This method appeals to people who have religious or moral objections to more direct forms of contraception, as well as those who want a completely side effect-free birth control experience. (Well, unless you count the side effect of a possible pregnancy.)
In response, Natural Cycles released a statement to The Verge stating:
“No contraception is 100 percent effective, and unwanted pregnancies is an unfortunate risk with any contraception. Natural Cycles has a Pearl Index of 7, which means it is 93 percent 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.”
Determining when, how and if you get pregnant is a very personal decision, so doing your research ahead of time is crucial when deciding on birth control. And when in doubt, a nonhormonal barrier method like a condom (yes, there are latex-free versions for those with allergies) may be a good idea.