Women's Health

Should Your Patient Use an Ovulation App to Monitor Her Cycle?

Women have relied on calendars and basal body thermometers for years to track fertility. In the age of smartphones, using an ovulation app provides new clarity.

Women have relied on calendars and basal body thermometers to track their fertility for years. But what about an ovulation app? In today's age of smartphones and fitness trackers, women are turning to mobile technology to stay on top of their menstrual cycles. Gynecologists and other clinicians can expect their patients to start inquiring about ovulation apps. Here is what to know so you can guide women to the best choice for them.

Apps, Apps Everywhere

Fertility-tracker apps now number in the hundreds, and they employ different approaches to track fertility. Some rely on data such as basal temperature to predict ovulation; others use period tracking, based on information users enter about their cycles. There are also apps that simply resemble digital menstruation calendars that allow users to log and track cycles over time.

Although most ovulation apps are likely used by people of reproductive age who are trying to become pregnant, users are relying on some apps as birth control. Earlier this year, the U.S. Food and Drug Administration allowed marketing of the first app that can be employed as a contraception method. The Natural Cycles app uses an algorithm that calculates fertility based on daily body temperature readings and menstrual cycle information — a method of contraception called fertility awareness.

How Effective Is Ovulation Tracking as Birth Control?

Ovulation apps vary in their level of detail. Some can help users log and track an impressive amount of information, including menstrual flow, cervical mucus, temperature, weight, mood and sex drive. Others chart the length and intensity of menstrual flow. Is an ovulation app birth control, though? Make it clear to patients that this is not the case: An ovulation app simply helps the user predict the timing of her next period as well as days of highest and lowest fertility during her menstrual cycle. 

The best-known fertility apps include:

Research suggests that fertility-tracking and ovulation apps are not perfect. A 2017 study from the University of Washington found that they were generally disappointing in terms of efficacy and ease of use. After collecting data from 2,000 reviews of popular period tracking apps and surveying 687 people, researchers concluded that the algorithms and assumptions used in some of the apps were not accurate enough to correctly predict menstrual cycles, especially if women had irregular periods.

Those same pitfalls may explain why contraception apps are not infallible either. Clinical studies to evaluate the effectiveness of Natural Cycles found that 1.8 in 100 women who use the app as directed for one year will still become pregnant. Ovulation apps have a typical-use failure rate of 6.5 percent, which accounts for women sometimes using apps incorrectly. Additionally, one report from a hospital in Sweden — where Natural Cycles was developed — found that 37 out of 668 patients seeking abortions had used ovulation apps as their primary form of contraception.

What's a Physician To Do?

There is no need to discourage people who want to track their menstrual cycles and fertile days from using ovulation apps, but clinicians should warn patients that they are not foolproof and do not physically prevent pregnancy. Although they can certainly help inform women about fertility, these products cannot promise precise predictions. Patients should know that they are not necessarily a reliable form of contraception — they are about as effective as other types of fertility awareness, such as the rhythm method.