Diana Diller’s decision to use pregnancy-tracking app Ovia also meant that her employer would learn intimate details about Diller leading up to and through pregnancy. Her employer also had access to aggregate information on workers using Ovia's fertility, pregnancy and parenting apps on the number of high-risk pregnancies or premature births, and on how quickly workers planned to go back to work.

Diller, an event planner in Los Angeles for video game manufacturer Activision Blizzard, agreed to use the app and give her boss access to information in exchange for $1 a day worth of gift cards. “Maybe I’m naive, but I thought of it as positive reinforcement: They’re trying to help me take care of myself,” says Diller, 39. The cash was “diaper and formula money,” she notes.

While such apps may be a fun way for women to track their pregnancies, some experts are concerned that employers can leverage the data to eventually increase healthcare costs or cut back healthcare benefits. Another concern is women’s personal information being vulnerable to breaches.

“What could possibly be the most optimistic, best-faith reason for an employer to know how many high-risk pregnancies their employees have?” asks Karen Levy, a Cornell University assistant professor who has researched family and workplace monitoring. “So they can put more brochures in the break room?"

“The real benefit of self-tracking is always to the company,” Levy adds. “People are being asked to do this at a time when they’re incredibly vulnerable and may not have any sense where that data is being passed.”

The protection of private health data was a big enough concern for Democratic and Republican U.S. Senators to introduce a new bill to protect that information, Homeland Security Today reports. Amy Klobuchar, a Democratic Senatory from Minnesota and a 2020 presidential candidate, and Lisa Murkowski, a Republican Senator from Alaska, are co-sponsoring the Protecting Personal Health Data Act. It would mandate “the Secretary of Health and Human Services to promulgate regulations for new health technologies such as health apps, wearable devices like Fitbits, and direct-to-consumer genetic testing kits that are not regulated by existing laws,” according to Homeland Security Today.

“New technologies have made it easier for people to monitor their own health, but health tracking apps and home DNA testing kits have also given companies access to personal, private data with limited oversight,” Klobuchar says. “This legislation will protect consumers’ personal health data by requiring that regulations be issued by the federal agencies that have the expertise to keep up with advances in technology.”

In a study published in April, the journal JAMA Network Open found that people using health apps to combat depression or to quit smoking may be unknowingly sharing their personal information to Google, Facebook and other third parties, The Washington Post reports. And many health apps are not beholden to government regulations, the report's researchers note.

“Digital data doesn’t go away,” John Torous, a co-author of the report, tells The Washington Post. “A part of the risk is that we don’t fully know who is going to put this data together, when and where it’s going to show up again and in what context. … Data seems to end up in the hands of the wrong people more and more."