Fertility apps promise to simplify a woman's life in an essential way — they can ????? ???????? ??? ?????help her avoid pregnancy or understand when she's most fertile. 

But a new study reveals that many of these apps can't live up to their potential. That failure poses a significant risk for women who stake their family planning choices on a smartphone.   

The study, which appears in the forthcoming issue of The Journal of the American Board of Family Medicine, identified 95 fertility apps between 2013 and 2015, and developed a tool to evaluate and rank them. 

The researchers immediately excluded 55 of the apps from the study because they included a disclaimer against using the product for pregnancy prevention or were not based on a proven fertility awareness-based method. Only six of those apps had a perfect accuracy score or didn't return a false negative by telling users they were infertile when they could actually conceive. 

Dr. Marguerite Duane, a family physician and the study's lead author, worries that the dismal performance of most apps will lead women to reject natural family planning when they should instead abandon a poorly designed digital tool.  

"This is the best kept secret we keep from women about how their bodies work." 

Duane, who specializes in teaching her patients fertility awareness, said there are six proven methods that prevent pregnancy without the use of hormones.

When using these techniques, women chart daily observations and physical signs like body temperature, cervical mucus and urine hormone levels to determine when they're fertile instead of relying on chemicals or artificial barriers like condoms to avoid getting pregnant. 

The major problem, Duane said, is that many doctors aren't taught these methods and don't share them with their patients. 

Duane, an adjunct associate professor at Georgetown University School of Medicine, believes that's partly due to questions about their efficacy. The failure rate for natural family planning, according to the Centers for Disease Control and Prevention, is 24% compared to less than 1% for intrauterine devices and 9% for the pill. Duane, however, has questioned that figure, noting that it reflects survey responses from women who report using the so-called rhythm method, which is considered outdated. 

By not sharing information about fertility awareness with their patients, Duane said, doctors deprive women of the opportunity to learn about their bodies and consider alternatives to hormonal birth control, which can lead to side effects like blood clots, mood changes, weight gain and hair loss. 

"This is the best kept secret we keep from women about how their bodies work," she said. 

Apps could theoretically help women practicing fertility awareness predict the days they're most likely to conceive, but most aren't very effective, said Duane. 

"You don’t have to be a rocket scientist to use these methods effectively."

The study's researchers used a dataset of seven cycles of daily fertility observations to test apps and found that, in some cases, they didn't actually use the symptoms entered by users, but instead operated more like a period calendar tracker. Others didn't incorporate evidence-based fertility awareness-based methods.

The study ranked Ovulation Mentor, Sympto.org, iCycleBeads, LilyPro, LadyCycle and mfNFP.net as the best phone- and web-based apps that predict the window of fertility. The apps NFP Charting, Fertility Pinpoint and Kindara didn't predict fertility, but still scored high on accuracy because they required users to understand a fertility awareness-based method.

Duane warns women against relying solely on even the best-performing apps. Instead, she said they should learn how to use a proven fertility awareness-based method from a trained educator and then turn to an app for tracking assistance. (The Fertility Appreciation Collaborative to Teach the Science, of which Duane is the executive director, maintains a list of educators.)  

"You don’t have to be a rocket scientist to use these methods effectively," she said. "Women are smarter than smartphone apps." 

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