Lawmakers are sounding the alarm on Big Tech to ensure that menstruation and fertility tracking apps are not sharing users' health data without their consent.

Democratic lawmakers from New Jersey Sen. Bob Menendez, U.S. Rep. Bonnie Coleman and U.S. Rep. Mikie Sherrill sent letters on Tuesday to tech conglomerate Apple, Google and Samsung requesting the major app providers halt allowing period tracking apps to share users' health data with third parties when they begin to use these apps. The letters were addressed to top executives of each tech company's app store platforms.

Both lawmakers are urging the tech giants to remove period tracking apps responsible for a "serious invasion of privacy" and to share more information on the privacy standards and sharing notices of the period tracking apps available on their platforms.

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"Your company is well aware of the gaps in data security and instances where a user’s personal information and data was sold without the user’s explicit consent and knowledge. The continued failure of your industry to be out front on these issues and consider the best interests of your users, especially on reproductive health data, shows either a glaring disregard for privacy concerns or gross incompetence," the letter states.

Women use menstruation and fertility tracking apps to monitor menstruation, prevent pregnancy or to boost their chances of conceiving. Many of these apps require users to input details on their sexual activity, menstrual cycle and birth control usage. And that doesn't exclude personal information such as full name, email address, age and weight.

A study conducted by Consumer Reports found that some of the most popular period tracker apps share users' health data with marketers for targeted advertising and even health researchers without their prior consent. According to research by Privacy International, a U.K.-based registered charity, 61% of menstruation apps tested automatically transferred data to Facebook as soon as the user opened the app.

"It is critical that women are able to make informed choices about their reproductive health and data; and that includes how reproductive health data is shared," the lawmakers stated.

This letter comes after a surge of privacy breaches of user data from tech giants and Congress' efforts to set regulations to hold Big Tech accountable.

Follow Jazmin Goodwin on Twitter: @jazminkgoodwin.

This article originally appeared on USA TODAY: Apple, Samsung, Google get letter from lawmakers to protect data from period tracker apps