Some corners of corporate America have a new message for new parents: Put down that laptop and pick up your baby instead.

Even as employees are increasingly tethered to the office, a workplace culture that urges new mothers and fathers to hurry back to their cubicles is beginning to shift.

In recent weeks, companies like Accenture and Microsoft said they would offer more family-friendly benefits like generous parental leave. The trend may be a sign of a tightening job market, at least for a certain segment of highly skilled performers.

But it also raises the question of whether these new benefits will be more talked up than actually taken. Employees may wonder if doing so is acceptable or if it could hurt their careers. At many companies, the new benefits are at odds with a highly demanding, 24/7 workplace culture — a culture that starts from the top.

On Monday night, Marissa Mayer, the chief executive of Yahoo, announced that she was pregnant with twins — and that no one should expect her to take much time away from work when they are born. “I plan to approach the pregnancy and delivery as I did with my son three years ago, taking limited time away and working throughout,” she wrote in a post on Tumblr.

Such contradictory signaling from Yahoo, which lengthened its parental leave in 2013, is typical and ambiguous, said Joan Williams, director of the Center for WorkLife Law at the University of California, Hastings. “The underlying work culture sends the message that if you’re really committed, you’re here all the time,” she said.

One after another, major companies are announcing more family-friendly policies. Accenture, the global consulting firm, said last week that primary caregivers would not have to travel for the first year of their children’s lives.

Microsoft nearly doubled to 20 weeks its paid leave for women who have just given birth, tripled paid leave for all other new parents and began offering them the chance to ease back into work half-time. Adobe Systems also significantly increased paid leave.

Netflix went the furthest: It will offer fully paid leave for new mothers or fathers for an entire year after a baby’s birth.

These companies are in the vanguard of a movement, some experts believe. “We’re in the midst of revolutionary changes in the workplace,” said Stew Friedman, director of the Wharton Work/Life Integration Project at the University of Pennsylvania. “It will be a 15- to 20-year project, but the competitive pressures in the labor market are pushing toward greater freedom and flexibility.”

At the same time, the new benefits are an acknowledgment that the American economy is struggling to adjust to modern gender roles and the rise of two-income families. As work hours have increased, and in the absence of government policies like paid parental leave, the work-family juggle has become daunting for many workers at all income levels. More than half of nonworking Americans say family responsibilities are a reason they are not working, according to a New York Times/CBS News/Kaiser Family Foundation poll.

Just 12 percent of workers in the United States private sector have access to paid family leave, according to the Department of Labor. White-collar workers are often expected to have a singular focus on work: Amazon, which a recent New York Times article showed fosters a bruising atmosphere, offers no paternity leave. For blue-collar workers in most companies, leave is even less common. Netflix, for instance, did not give its leave to hourly workers.

One reason some companies are doing this now is that millennials, the biggest generation in the work force, have higher expectations for gender equality at home and for accommodations from their employers. Highly educated women have become more likely to believe that an ambitious career does not preclude children. And the competition for elite workers has become so fierce that companies are searching for new ways to recruit and retain them.

“The U.S. may be behind on family-friendly benefits, but I see it’s changing, because we’re all facing a talent war,” said Julie Sweet, Accenture’s chief executive of North America.

This summer, Goldman Sachs doubled its paid paternity leave to four weeks. IBM and Accenture said they would ship breast milk home for nursing mothers traveling for work. On Tuesday, Twitter told Fortune it would offer the same milk-shipping service. Nestlé expanded its paid maternity leave to 14 weeks from six. Vodafone expanded its maternity leave and said new mothers could work 30 hours a week at full pay for their first six months back. And at KKR, the investment firm, if new parents are traveling on company business, the firm will pay for a nanny’s plane ticket, meals and hotel room.

Tech companies are in a constant battle for star engineers, so their recent announcements might have been promotional as much as anything. Lauren Edelmeier, a senior manager in design research and development at Microsoft, where up to 4 percent of workers are out on parental leave at any one time, is in the middle of her 20-week paid leave with her 3-month-old daughter Vivian.

“I feel really fortunate to have this time at home,” she said. “I’ve been able to watch her grow, and she knows who I am.”

Yet office culture heavily influences whether people feel they can take their full leave. The 35-year-old father of a baby in San Francisco was offered 12 weeks of paid leave in his government job, but took half.

“It was phrased like, ‘Take all the time you need.’ It was not phrased, ‘We’ll see you in 12 weeks,’ ” he said, declining to have his name published because of the sensitivities of the issue in the office. “It puts it all on the employee, and you want to prove you’re good and valuable.”

Social scientists warn that family-friendly benefits can backfire. In general, women are more likely to use them, while men either put less priority on family or make informal accommodations to work more flexible hours. A result is that women, but not men, are seen as less committed to work.

Perhaps that is why Ms. Mayer, in her post, emphasized that she was committed to both her job and her family, an explanation not typically heard from male executives with children.

To address these issues, companies have tried various methods to encourage all employees to use the benefits.

At Facebook, which gives mothers and fathers four months off, fully paid, senior executives talk publicly about leave to show employees it’s acceptable. It remains to be seen whether Mark Zuckerberg, the chief executive, will take the full four months when his baby is born.

Microsoft, which used to pay for just a portion of parental leave, decided to pay for all of it as a symbol of its support.

“We fully expect to have close to 100 percent uptake,” said Fred Thiele, senior director of global benefits at Microsoft.

At Accenture, primary caregivers are automatically enrolled in the no-travel policy, instead of opting in.

“People don’t have to think, ‘What will people think of me if I actually choose to do this?’ ” said Ellyn Shook, its chief human resources officer.