Women use menstruation tracking apps for a range of reasons, from monitoring their period cycles to maximize their odds of conceiving a child, but a new research discovered that some of these apps could compromise their users' information.

Menstruation Tracking Apps Share Sensitive Information With Facebook

The new research conducted by UK-based advocacy group Privacy International discovered that some period-tracking apps used by women were sharing sensitive data with Facebook.

Apps like Maya by Plackal Tech and MIA Fem: Ovulation Calculator by Mobapp Development Limited reportedly shared large amounts of sensitive information with Facebook and other parties.

The report said Maya starts sharing some data with Facebook even before the user agrees to the app's privacy policy. These user data include menstruation symptoms, monthly periods, and when the user logged contraception use.

"When Maya asks you to enter how you feel and offers suggestions of symptoms you might have — suggestions like blood pressure, swelling or acne — one would hope this data would be treated with extra care," the report reads, according to Buzzfeed News. "But no, that information is shared with Facebook."

Maya has more than 5 million downloads on the Google Play store, while MIA Fem has more than 2 million users around the world. These apps are also available on the App Store.

Privacy International also found that Ovulation Calculator by Pinkbird, My Period Tracker by Linchpin Health, and Mi Calendario by Grupo Familia also notified Facebook when the user opened an app.

Not all tracking apps shared user information though. The research found that some of the most popular period-tracking apps, including Period Tracker by Leap Fitness Group, Period Tracker Flo by Flo Health, Period Tracker by Simple Design, were not sharing any data with Facebook.

Facebook Can Detect And Delete Personal Data

A Facebook spokesperson said the company requires app developers to be clear with users about the information they share with Facebook, and added that the platform now has systems that can detect and delete certain types of data such as email, phone number, and other personal data.