Deirdre McMurdy

If Marissa Mayer wasn't used to raising eyebrows before July 16 when she was named CEO of Yahoo, she'd better get used to the attention fast.

Eyebrows were raised at her appointment — interim boss and Yahoo veteran Ross Levinsohn was expected to get it. Then there was the fact that despite her impeccable credentials as a software engineer and her senior role at Google (as one of Google's first employees, she is now worth an estimated $300 million), she has never managed an entire company — particularly an ailing one with wobbling ad sales and a delicate international e-commerce alliance with a Chinese venture, Alibaba.

They were raised again when public documents disclosed she'd make over $70 million through a combination of salary, bonuses, stock grants and options over five years at Yahoo. Then Mayer announced she was pregnant.

Of all the many challenges and eyebrows she faces, the fact she's expecting a baby this fall seemed to cause the greatest stir of all. It wasn't her appointment that made the front page of U.S. News and World Report, it was her pregnancy and her declaration that she would work before and after the birth of her son.

Not to say there's a shortage of corporate diapers to change at Yahoo.

With the singular example of Apple's resurrection by Steve Jobs, it's notoriously difficult for high-flying tech companies to regain altitude once it's lost. As has happened at Yahoo, companies stagger from leader to leader, losing momentum and market identity each time another rescue plan fails. Mayer is the fifth CEO — including two interim appointments — in three years.

The number of fresh, nimble upstarts, furthermore, makes these troubled companies look clumsy and stale and dated, the corporate equivalent of mutton trying to dress as lamb. Few things are less attractive to customers or shareholders — as RIM knows too well.

Just the day after Mayer took the helm of Yahoo, it reported Q2 results showing overall revenue stagnant at $1.2 billion and softer net income of $227 million. Worse is the decline of online ad revenue upon which Yahoo feeds.

The first 90 days of a new CEO's tenure are said to be the most critical in determining success or failure. That's the time for setting the course, establishing priorities, creating a new tone and pace with employees and shareholders, and flagging any strategic shifts in direction. But for Mayer, the public debate — and judgment — of a very personal situation is likely to overwhelm everything else.

Among the ranks of Fortune 500 companies, only eighteen are women. Over 40 per cent of women in full-time professional careers are childless.