Digital Contraceptive Provides Natural Birth Control Method

A novel mobile application uses a smart algorithm that is sensitive to subtle patterns in a woman's cycle to determine daily fertility, based on basal body temperature (BBT) and period data.

The Natural Cycles (Stockholm, Sweden) app is an effective, natural method of contraception that combines an intelligent algorithm and a BBT thermometer to identify fertility status. To use the app, BBT, the body’s lowest resting temperature, should be measured at least five times a week first thing in the morning, when waking up. After ovulation occurs during the menstrual cycle, there is a detectable rise in BBT caused by hormones; by noting BBT, the app can calculate fertility. Additional data, such as luteinizing hormone (LH) test results and sex frequency can also be entered to help the algorithm build a unique cycle.

In a real-world observational study of the mobile app, 54,372 women who had at least 20 data entries were evaluated. For each country group, contraceptive effectiveness was calculated as a typical use one-year Pearl Index (PI). The results showed that the Natural Cycles app was between 92.5% and 94.9% effective according to the typical use PI, depending on the country. PI was 6.1 in the United States, 5.8 in the United Kingdom, 5.1 in Australia, 7.5 in Finland, and 6.1 in Sweden. The study was presented at the 2018 American Society for Reproductive Medicine (ASRM) meeting, held during October 2018 in Denver (CO, USA).

“Because every women is unique and her cycle is unique, you need to apply statistical scrutiny to understand when can you definitely say that if you have unprotected intercourse today it will not lead to pregnancy, and that is all about probabilities,” said Elina Berglund, PhD, co-founder and CTO of Natural Cycles, in an interview with TechCrunch. “So you have to combine the probability of sperm survival, how well you know the ovulation pattern of this women, how well you see the temperature pattern for this particular woman to detect do you really know that she has ovulated, and how well do you assess when she has ovulated and to be able to predict that.”

BBT is the lowest temperature attained by the body during rest (usually during sleep). It is generally measured immediately after awakening and before any physical activity has been undertaken, although the temperature measured at that time is somewhat higher than the true BBT. In women, ovulation causes an increase of one-half to one degree Fahrenheit (one-quarter to one-half degree Celsius) in BBT; monitoring of BBTs is one way of estimating the day of ovulation. The tendency of a woman to have lower temperatures before ovulation – and higher temperatures afterwards – is known as a biphasic pattern, which can be used as a component of fertility awareness.

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Natural Cycles