New York:Depending solely upon your smartphone app to help avoid or achieve pregnancy may not be a very good idea, warn researchers. "Smartphone apps are increasing in popularity because more and more women are interested in using natural or fertility awareness-based methods (FABMs) of family planning because they want to feel empowered with greater knowledge of their bodies," says lead researcher Marguerite Duane, Associate Professor at Georgetown University in the US. However, a review of fertility awareness apps showed that most apps do not employ evidence-based methodology, researchers found. Though the apps offer a convenient way to track fertility biomarkers, only some of them employ evidence-based FABMs. Further, "the effectiveness of FABMs depends on women observing and recording fertility biomarkers and following evidence-based guidelines", Duane elaborated. Success using FABMs depends on many factors, including the ability to accurately make and classify daily observations. However, relying solely on an FABM app may not be sufficient to avoid pregnancy, the researchers said. In addition, many apps also include a disclaimer discouraging use for avoiding pregnancy. For the review, published in the Journal of the American Board of Family Medicine, more than 95 apps were identified on iTunes, Google, or Google play. Of those, 55 were excluded from evaluation because they either had a disclaimer prohibiting use for avoiding pregnancy or did not claim to employ an evidence-based FABM. "Of those reviewed, 30 apps predict days of fertility for the user and 10 do not. Only six apps had either a perfect score on accuracy or no false negatives (days of fertility classified as infertile)," Duane commented. Apps that do not predict fertile days scored high on accuracy only if they required that women receive training in an FABM prior to using the app. "When learning how to track your fertility signs, we recommend that women first receive instruction from a trained educator and then look for an app that scored four or more on mean accuracy and authority in our review," Duane noted.