- Natural Cycles is a non-hormonal birth control app that uses daily temperature readings to determine when someone is most likely to get pregnant and should abstain from or have protected sex.
- The app’s creators said it is 93% effective, but reports of dozens of women becoming pregnant while using the app have raised concerns.
- Natural Cycles‘ VP of Science and Communication Anita Kraker von Schwarzenfeld told INSIDER there’s a 7 in 100 chance that a woman will have an unplanned pregnancy while using the app, even if she does everything right.
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Instead of relying solely on pills and IUDs for birth control, women are increasingly turning to apps to track everything from their periods to their fertility.
One of the most popular apps comes from Natural Cycles, a Swedish company that uses a thermometer- and algorithm-based system to track signs of fertility and tell women when they should abstain from or have protected sex.
Natural Cycles is a non-hormonal birth control option – an attractive choice for women who have had unwanted side effects from other birth control methods like the pill and implants.
The app requires women take their basal body temperature with a thermometer daily. Then, an algorithm uses that data to determine when she is most likely to become pregnant each month and suggests abstaining from sex or using another birth control method like a condom during that time.
But the app isn’t entirely reliable. In January 2018, complaints from 37 Swedish women who got pregnant while using Natural Cycles raised concerns about the product’s effectiveness as a contraceptive.
At an event in New York City, Natural Cycles VP of Science and Communication Anita Kraker von Schwarzenfeld confirmed the app isn’t 100% effective as a primary form of birth control
“7 out of 100 women using [Natural Cycles] will have unplanned pregnancy,” Kraker von Schwarzenfeld told INSIDER.
She was referring to a peer-reviewed study of Natural Cycles that looked at more than 4,000 women between the ages of 18 and 45, which found that the app’s failure rate is 7% for “typical use.”
“Typical use” refers to how the general population, rather than people in a clinical trial, would use the product. It accounts for errors like taking your temperature at a different time than usual or having unprotected sex on a day when the app suggests abstaining or using protection.
If a woman uses the app perfectly every time, there is 5 out 1,000 chance of getting pregnant. After Advertising Standards Authority (ASA), a UK-based organization that ensures companies are fairly advertising their products, launched an investigation into Natural Cycles, the organization found that just 9.6% of inputted cycles in the app could be considered “perfect-use.”
Natural Cycles provides birth control for women who don’t want to use a hormonal method
Natural Cycles co-founder Raoul Scherwitzl has spoken about the efficacy of the app in the past, saying that “Just like with the pill you have scenarios where women take the pill everyday” and it’s very reliable, but if a person doesn’t use it correctly on daily basis, the effectiveness decreases. There is a 9 out of 100 chance a woman will get pregnant while using a birth control pill because of imperfect use, according to the Centers for Disease Control and Prevention.
When the Food and Drug Administration approved Natural Cycles, the company said the product was 93% effective at preventing pregnancy, but the ADA investigation found it was closer to 91.7% effective.
“We are upfront about the effectiveness and [ask] women upfront ‘How okay are you with the potential of an unplanned pregnancy?'” Kraker von Schwarzenfeld said. The Natural Cycles website includes a page that explains perfect use versus typical use effectiveness rates and the reasoning behind them.
“It’s important to ask yourself before using Natural Cycles whether you would be willing to use protection or abstain from sex on red days. If the answer is no, you should talk to a doctor about a more suitable method of contraception,” the site reads.
For this reason, Natural Cycles may be an birth control method best suited for people who are thinking about having a child in the near future anyway. But for women who aren’t considering children due to their age, health, or other factors, a birth control method that relies on consistency, abstinence, and a second birth control method could be problematic.
“In the end, what we want to do is add a new method of contraception that women can choose from without side effects,” Scherwizl previously told Business Insider. “I think there are many women who this will be great for.”