Yahoo’s choice of Marissa Mayer as its new chief executive broke the proverbial glass ceiling that prevented women from heading large companies while pregnant.

Mayer promised that when her child arrives she’s going to take just a few weeks of maternity leave, and she’ll “work throughout it.” That’s great for Yahoo shareholders, but how great will it be for her or her baby?

I’ve no doubt that Mayer will serve as a much needed role model for pregnant working women. But I worry she might be sending the message, even if unintentionally, that maternity leave shouldn’t be in the cards for women in leadership positions in the corporate world.

I had the luxury of taking three paid months off from my job, and I’m not sure Mayer will really understand the reality of intense sleep deprivation until she’s having her own sleep interrupted three or four times a night for weeks on end.

What’s sad, though, is the lack of recognition and respect given to female corporate bigwigs who take maternity leave and completely immerse themselves in caring for their baby.

Yes, Yahoo sent a strong feminist message by hiring a “pregnant CEO,” but how much more reassuring would it be if the company also gave her the option of taking a real maternity leave when the time comes?