First, I think that everyone in this thread should read or reread
http://www.paulgraham.com/say.html because it is very relevant.
What is my point? It is no more or less than that childbirth takes a huge and often unpredictable toll out of women. What toll it will take out of any particular woman is difficult to predict. In most cases the toll is far larger than the people involved expected. Any woman coming into motherhood, particularly for the first time, is naive if they think that they can plan to put motherhood in a box and be confident that it will actually stay there.
This is different for men. If a man with sufficient resources decides that he does not want his work to be impacted by fatherhood, it won't be. Whatever the cost to his family or the opinion of his friends, he really can ignore parenting and continue to work normally. I would not personally choose that, and men who choose to be involved with their children open themselves up for some of the same issues that women go through. But I am confident a high powered male executive who promises that has very low risk of failing to deliver on that promise.
You dismiss this by calling it bigotry. I claim that I'm on very solid grounds here based on statistics and biology. I think that having even a casual acquaintance with the facts, or having some personal acquaintances with some horror stories, puts me on solid ground to say what I did. (For example I know one woman who had problems with water retention that caused severe carpal tunnel. She was unable to pick anything up, drive, use a mouse or keyboard, etc for months. Good luck with that!) Calling me a bigot invokes a taboo, I'm a horrible person for thinking those thoughts, but it says nothing one way or the other on whether I am right.
All of that said, Marissa is a truly impressive woman. She brings a lot to the table here. There is a reason why she has triggered more discussion than anyone else in the previous parade of CEOs that Yahoo has had recently. Her pregnancy is an obvious risk factor for her, and it is silly to try to claim otherwise. But that is a risk, not a guarantee. Most women do not have particularly difficult pregnancies. Many women are able to balance babies and work. But you can't plan on this in any particular case. And she is likely to get a surprise about how much work it is.
Now let's turn to your attempts to personally attack me.
The same biology makes us different so that there are women like your wife, who finds Mayer's plan laughable, and women like Mayer herself, with her two comp-sci honors degrees from Stanford, famously long hours, etc.
It seems that you think I have a stay at home wife who has never done anything in her life. Nothing could be further from the truth. My wife has a PhD in biology from Dartmouth College, and an MD from NYU (one of the top medical schools in the country) earned with honors. Can you claim accomplishments of similar difficulty? Can you honestly claim to have done anything with close to the effort of a medical internship? If your answer is no, then you're in the same boat that I am. I have great respect for my wife.
My wife's opinions do not come from an inability to work hard. They come from her knowledge and experience of what motherhood can take out of women.
Since you like un-PC, factual conversations about hormones, let's turn this around and talk about you. Fair is fair. Have you ever thought how remarkably ill-suited you as a male are to system design and coding? How do you, a highly-hormonal young man who spends an inordinate chunk of his time thinking about sex, ever get any work done, in a profession where continual focus is paramount? And is it fair to your two children that you spend so much time on HN and SO, the time that could instead be spent furthering their IQ?
Thank you for calling me young, at almost 43 I have not thought of myself that way for years. I also spend rather less time thinking about sex than you seem to imagine.
As for my children, my wife is right now going through a medical residency. I therefore am a full-time parent who does part time contracting on the side. Sure, I spend time on NH and used to on SO, but you may rest assured that my children are not be compromised by that. (If you go back I said that having children has limited my ability to work hard, now you know why.)
(If above seems like a personal attack, please consider that your opinion that a woman has to choose between motherhood and work is very personal to female HN readers like me.)
Please stop projecting opinions on me that I do not have. Talk to what I am saying, and not the straw man argument that you think I said.
As my personal life makes clear, I not only do not believe that a woman has to choose between motherhood and work, but I am personally making serious professional sacrifices right now to allow my wife to achieve what she wants to achieve.
If this surprises you, then I highly recommend that you go back and read what I wrote to try to figure out what I actually think. Because what I'm saying really isn't that unreasonable.
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Update
I wrote that before your edit. Thanks for the kind words. I suspect that my opinions may be more equitable than you thought, but the opinions that you don't like are unlikely to change. They are not what I want the world to be, but are observations of how it actually seems to work.
On postpartum depression, I was looking for a condition that hits lots of women, and it was the first that popped into my mind, and the first link I found for it said 10%. Now that I look at it in more detail I find that there is disagreement on what it is and when people have it, on the frequency, and a lack of clarity on the causes. Indeed there likely are many factors that contribute. Many of the causes you'll find in the literature are tied to hormones and biology. Many are not. That was a bad example.
A better example would be Caesarian section. Caesarian sections are very common, and the usual recovery time for women is 4-6 weeks. Which is significantly longer than the 2 weeks that Marissa is planning on. Obviously being a CEO is not a physically demanding job, if need be she could do it from a wheelchair. But recovering from major surgery is likely to hamper her performance.