Glow’s issues also shine a light on the regulatory gray zone that encompasses period-tracking, fitness trackers and other health-related apps. The data users put into the apps aren’t automatically covered by HIPAA, the federal health privacy law that shields, for instance, information shared with your doctor. Instead, the Food and Drug Administration has said it would exercise "discretion" on whether it would pursue privacy violations by many health apps.
“This kind of information for women is very intimate,” Patient Privacy Rights founder Deborah Peel said. “The implications are really huge: There are absolutely no laws that protects that information from being sold, disclosed, or traded — for any purpose, be it marketing or research.”
Although HIPAA-based regulation has rules about data security, fertility- and period-tracking apps generally aren't required to go through security testing before they make it onto users’ smartphones. But Consumer Reports did its own security audit of Glow and found several problems.
The most troubling involved a feature in which a Glow user could link their account with another person to share information. But Consumer Reports discovered that anyone who knew a user's email address could start getting that data without the user's explicit permission. That means practically anyone, including stalkers or abusive exes, could have found a window into the intimate data the app tracked.
Glow, which was developed by a tech incubator started by PayPal co-founder Max Levchin, worked quickly to fix the problem after Consumer Reports told the developers about the issue. It also sent an email to users informing them about the bug and advising them to check their linked accounts.
"Of the more than 4 million users across our apps, far less than 0.15% of our users could have potentially been impacted, but there is no evidence to suggest that any Glow data has been compromised," Jennifer Tye, the head of Glow's U.S. operations, said in an emailed statement.
Last fall, Glow said it helped more than 150,000 couples conceive and promoted research that it said showed that users who meticulously tracked ovulation cycles in the app were 40 percent more likely to get pregnant than casual users. But, as Wired reported at the time, some experts were skeptical that Glow was really the reason those couples got pregnant.
In an interview, Tye told The Post that the company's apps don't seek to replace services offered by fertility specialists. Instead, Glow's apps "help women and couples track various aspects of their reproductive health." Having that information on hand could help those struggling with infertility work through the issue with their doctors, she said.
However, a recent study published in the Journal of the American Board of Family Medicine found that many popular fertility- and period-tracking apps struggled to accurately predict when women were most fertile — with Glow ranking near the bottom of the reviewed apps.
Despite concerns about their effectiveness and Glow's security problems, the market for these apps is still booming — several of them rank high on Apple's App Store listing of health and fitness apps.
"Generally, our policy is very consistent with what lots of other companies out there say," said Tye, the Glow executive. She said the app does not currently feature marketing or advertising from other brands.
A 2014 Federal Trade Commission study of the larger health app market, in which period-tracking apps are a major player, also found that many of the apps the agency reviewed shared users' information with third-party advertising and analytics firms.
Concerns about privacy and security have left some experts skeptical about fertility- and period-tracking apps operating outside of the traditional regulatory framework for health data. Although these apps could help researchers learn more about women's health, app-makers should also acknowledge they're "handling medical information that should be treated with the right safety precautions and confidentiality," Contreras said.
"There's definitely the need for some sort of HIPAA-compliant app that would allow a patient to directly communicate with physicians," she said.