I'm reading The Wife Drought by Annabel Crabb at the moment and it explores this kind of issue and the reason behind that question in-depth. I'm really enjoying it, anyone else reading it?
I have just finished it - I thought a very interesting read - lots of new things I didn't know about(the marriage bar), statistics and ideas. There was one quote I particularly liked from Christine Milne which was about considering a political career but could be about considering any career

"Just go into it with your eyes open and think about how you are going to stage your career. How long are you going to be there?What role, what level of responsibility? Is this the best time to do it? Have you got that level of support in your own relationship and family that will enable you to do the job well?"

I don't think I ever thought about it, I was naive I think, I thought it would be totally possible to do whatever I wanted and have children, it can be possible but only with the right framework - which might be your partner, your family, or outsourced support (childcare, in home help etc.), and some planning. I wish I had asked people more questions about how they have arrived where they are and how they manage it.

I also confirmed what I have always known - that I am a pretty lousy 'wife' - but then who is the 'wife' in our relationship fluctuates according to our jobs at the time, DH has been in the 'wife' role for more of our relationship than I have. DH is quite a good 'wife' he is better at most of it apart from the childcare than me.