Global Health News
Natural Cycles - Birth Control Without Pills Or Condoms
by L.D. Ramirez (info sourced from an Ars Technica article by Andrii Degeler, and a Bloomberg article by Esme Deprez
Swedish startup Natural Cycles takes on the pill with data science, a phone app, and thermometers.
Natural Cycles is a fertility-tracking app built by Raoul Scherwitzl and Elina Berglund in 2014. It’s the first, and still the only, mobile app cleared for marketing as a certified contraceptive in Europe and the U.S.
For women who need or want to abstain from birth control pills and their accompanying side effects, Natural Cycles provides a powerful alternative. The app allows its subscribers to log their body temperature daily, then applies a clinically-proven algorithm to predict the roughly one week per month during which a woman is fertile.
The body temperature fluctuations at the time of ovulation and right afterwards normally range from 0.25°C to 0.45°C due to release of the hormone progesterone. To accurately measure this, the user's thermometer needs to be put under the tongue, as the skin might not be sensitive enough.
The app shows fertile days as red - with peak fertility showing up as the darkest shade of red - and non-fertile days as green. If your goal is to prevent pregnancy, then hit the hay only on green-marked days. If your goal is to conceive, then get intimate during red-marked days.
"Our app is always extra cautious in the first months until it has enough data to safely give green days," says Elina. "On average, a woman that has just started using the app will get about 40 percent of green days a month. After the first three months of use, as the app becomes more confident, about 65 percent of days are shown as infertile days.
Natural Cycles app interface overview in pregnancy prevention mode.
Citing commercial interests, co-founder and CTO Elina Berglund declined to go into more detail about the startup’s complex algorithm, which is said to be 60 pages long. Howeverm it’s known that the parameters it takes into account are temperature, menstruation, and optionally LH (luteinizing hormone) test information. It also eliminates false positives by taking into account the cases when body temperature changes due to other reasons (e.g. sleep quality, alcohol consumption, illnesses, stress).
Although the method used by Natural Cycles doesn't work for everyone — there's a portion of women whose body temperature doesn't change consistently with ovulation — it's arguably a good alternative to traditional family planning methods.
By acquiring more users, the app arguably has a chance to become more accurate: the more data it gets, the better its algorithms should be at predicting the fertile and not fertile days of a woman's cycle.