https://web.archive.org/web/20190416160537/https://www.washingtonpost.com/te... Like millions of women, Diana Diller was a devoted user of the pregnancy-tracking app Ovia, logging in every night to record new details on a screen asking about her bodily functions, sex drive, medications and mood. When she gave birth last spring, she used the app to chart her baby’s first online medical data — including her name, her location and whether there had been any complications — before leaving the hospital’s recovery room. But someone else was regularly checking in, too: her employer, which paid to gain access to the intimate details of its workers’ personal lives, from their trying-to-conceive months to early motherhood. Diller’s bosses could look up aggregate data on how many workers using Ovia’s fertility, pregnancy and parenting apps had faced high-risk pregnancies or gave birth prematurely; the top medical questions they had researched; and how soon the new moms planned to return to work. “Maybe I’m naive, but I thought of it as positive reinforcement: They’re trying to help me take care of myself,” said Diller, 39, an event planner in Los Angeles for the video game company Activision Blizzard. The decision to track her pregnancy had been made easier by the $1 a day in gift cards the company paid her to use the app: That’s “diaper and formula money,” she said. [...] ...this new generation of “menstrual surveillance” tools is [...] designed largely to benefit not the women but their employers and insurers, who gain a sweeping new benchmark on which to assess their workers as they consider the next steps for their families and careers. [...] “The real benefit of self-tracking is always to the company,” Levy said. “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.” [...] “Each time we introduced something, there was a bit of an outcry: ‘You’re prying into our lives,’ ” Ezzard said. “But we slowly increased the sensitivity of stuff, and eventually people understood it’s all voluntary, there’s no gun to your head, and we’re going to reward you if you choose to do it.” “People’s sensitivity,” he added, “has gone from, ‘Hey, Activision Blizzard is Big Brother,’ to, ‘Hey, Activision Blizzard really is bringing me tools that can help me out.’ ” [...] Ovia began as a consumer-facing app that made money in the tried-and-true advertising fashion of Silicon Valley. But three years ago, Wallace said, the company was approached by large national insurers who said the app could help them improve medical outcomes and access maternity data via the women themselves. Ovia’s corporate deals with employers and insurers have seen “triple-digit growth” in recent years, Wallace said. The company would not say how many firms it works with, but the number of employees at those companies is around 10 million, a statistic Ovia refers to as “covered lives.” [...]