With hundreds of apps aimed to help women find the optimal time to conceive or avoid pregnancy, a new warning has been issued to not rely on the information these apps supply as they are ineffective.

A team of researchers from Georgetown University School of Medicine in Washington D.C. reviewed around 100 fertility apps commonly used by women in the U.S – around half of smartphone users have reportedly downloaded a fertility app. 

According to Dr. Marguerite Duane, lead researcher on the study, a growing number of reproductive-age women are using fertility awareness-based methods (FABMs) to help control whether or not they become pregnant. They aim to track menstrual cycles and optimum time for ovulation occurrence – the time best to conceive, according to a report in Medical News Today.

Out of the apps reviewed, only six were able to accurately predict ovulation times after conducting a five-point rating system that used 10 criteria considered important for avoiding pregnancy.

Surprisingly, 55 of the apps failed to use an evidence-based FABM to track information making them void of any use and eliminated from the study leading to a worry that many women are depending on these apps to correctly predict their fertility.

Duane says tracking your fertility is a much more complex process than just checking a smartphone 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.”

The study is due to be published in The Journal of the American Board of Family Medicine.