HispanicBusiness

As for an expected generation gap on Mayer's approach to the children-and-work dilemma, Graves says that's not necessarily so. There's little data, she says, noting that "we can't pin it down to age. It depends on the whole value of the person."

Deena Rosenberg, 29, of Teaneck, N.J., just returned to work at a public relations firm after a 12-week maternity leave for her first child. She says she has a friend, also 29, who questioned her decision to go back to work and put her son in day care.

But even Rosenberg has concerns about Mayer's plans to work during her official maternity leave.

"Her statement sets a bad precedent for other new moms and the corporations they work for that will now expect that to be normal maternity-leave behavior," she says. "The reality is that the initial days and weeks after having a baby is a difficult time physically and emotionally, and is also crucial to the formation of the mother-child bond."

Celebs make it look easy

High-profile women in areas such as business, politics and fashion have garnered headlines with their examples of what looks like an easy return to work.

Sarah Palin, who was governor of Alaska when she gave birth to her youngest son in 2008, was back on the job just three days later.

Model Heidi Klum gave birth in October 2009 and sauntered back onto the Victoria's Secret runway in November.

Then-expecting singer-turned-fashion designer Victoria Beckham told Glamour magazine in June 2011 that she planned to work right until her fourth child was born. "Maternity leave -- what's that?" she asked.

But as with Mayer, these women have resources that other working moms don't. They can hire full-time help. They are also in entrepreneurial or leadership roles that tend to give them more professional power than other workers.

Even with that cash and cach, some mothers predict that these women will lose out on certain things because of their demanding work schedules.

Elana Drell-Szyfer, CEO of cosmetics company AHAVA North America and a mother of three, says that working after her first child's birth was more difficult than she expected.

She figured she could manage business e-mails and other needs, but she was surprised by how much time it took to take care of her baby -- and by the drain on her.

"I was like, 'How hard can this be? It's a little baby and they sleep the majority of the time,'" says Drell-Szyfer, who was a high-level executive at another cosmetics company at the time. "But you have no idea about what is to come."

She recalls the night she realized she couldn't keep up.

While trying to nurse the baby and work on her laptop at the same time, Drell-Szyfer says she thought, "This is really wrong. I should be trying to bond with this child and I actually don't look professional trying to answer e-mails at 3 a.m."

Anne-Marie Slaughter, former director of policy planning at the State Department, wrote about the challenges of managing family and work in a widely read Atlantic magazine cover story titled "Why Women Still Can't Have it All."

"When my two-year public-service leave from Princeton University was up, I hurried home as fast as I could," she wrote. "When people asked why I had left government, I explained that I'd come home not only because of Princeton's rules (after two years of leave, you lose your tenure), but also because of my desire to be with my family and my conclusion that juggling high-level government work with the needs of two teenage boys was not possible."

A double standard?

In June 2011, gossip website Gawker reported that Google co-founder Larry Page was expecting his second child. That was two months after Page took the CEO title at the technology behemoth. There were no follow-up headlines, no social media debates, no loud conversations about how he could lead an Internet giant and still be a father.

As for Yahoo, its board didn't seem to flinch at Mayer's pregnancy. Company representatives and Mayer -- the company's fifth CEO in five years -- weren't available for comment, but in a news release, Yahoo board Chairman Fred Amoroso said Mayer's "unparalleled track record in technology, design and product execution makes her the right leader for Yahoo at this time of enormous opportunity."

Mayer, who was previously an executive at Google, said in the Fortune interview that Yahoo's directors "showed their evolved thinking."

As much as society has evolved, women still face the greater scrutiny when they decide to return to work after having children, says Rosalind Chait Barnett, a senior scientist at Brandeis University's Women's Studies Research Center.

"If a man was taking a job like this and his wife was going to have his first child, that would be a yawn," she says. "People won't be talking about it."

Women and men will wonder "if she can pull this off," she says. That scrutiny is "a burden that a man doesn't have to bear."