I recently received yet another inquiry from a woman asking me about one of the scores of fertility apps currently flooding the internet. While I find most of the apps concerning, one in particular worries me the most. The developers claim it is the first FDA-approved birth control app that purports to tell you when you are safe for unprotected intercourse. And therein lies the problem. “FDA approved.” I’m loath to mention its name for fear that women will run out and download it without understanding its most serious pitfall, which I will get to in a minute.  

When I first decided to write Taking Charge of Your Fertility back in the Stone Age of 1995, the internet had yet to dominate our lives. So back then, the thing that kept me up nights was my concern that women would maybe misunderstand concepts in the book, leading to unplanned pregnancies. 

Today, those fears seem almost quaint compared to a much bigger concern: the pervasiveness of scores of apps which claim to be able to predict a woman’s fertility based on nothing more than inputting the first day of her period (as do scores of bogus apps), or occasionally basal temperatures. In fairness, those that include basal temperatures might tell you when you are safe for unprotected intercourse after ovulation, but one of the huge drawbacks of these type of apps is that they claim to be able to predict upcoming preovulatory fertility using an algorithm based on past cycles . . . which is nothing more than a high-tech version of the obsolete Rhythm Method.

In order to judge whether an app is reliable, at a minimum, it should allow you to input your cervical fluid in addition to basal body temperature, as well as other secondary fertility signs such as ovulatory pain. Those that only include temps (as does the app that this woman asked me about called Natural Cycles) cannot indicate when ovulation is about to occur, but only confirm if ovulation has already happened. To know on a daily basis whether or not you are fertile before ovulation (since sperm can live up to five days), you need to observe and record your cervical fluid, which is critical for both contraceptors and pregnancy achievers.

Regardless, I encourage you to thoroughly read my book, Taking Charge of Your Fertility and take a class in the Fertility Awareness Method before using one of these apps, because they alone can’t possibly provide you with the instruction and personal counseling necessary to be able to understand how to rely on your primary fertility signs. And even with my own app, https://www.ovagraph.com,  I admit that it should be used only as a convenient way to always have your charts with you, and even to share them with a clinician or others. However, no app is a replacement for proper education about your body, fertility and cycles.