My OB told me an interesting story during one of my routine pregnancy checks:
When she was starting her residency, one of the first lectures the residents got was about how fertility declines sharply after age 30. She said it was kind of scary the way it was presented. And sure enough, a few months later, all the female residents in program were pregnant. (Lesson: Don't talk to your female residents about declining fertility!)
I had a baby at age 27, which is above the mean age for a first baby in this country (25, I think), but well below the mean age for a first baby amongst my colleagues. Of the fifty or so women I went to med school with, I know of only FIVE who have had kids, even though the very youngest of us are almost thirty. I remember on my Labor and Delivery rotation in med school, all the girls in my class used to joke about how when they were up on the L&D board someday, there'd by an "AMA" note by their name. (AMA = Advanced Maternal Age)
When I first started my residency, I felt like a pregnant teenager. I was the youngest of all the residents (the oldest of the bunch being close to forty) yet I was the only one who was even close to being a parent. Of course, most of them were single guys, who talked about barhopping at lunch while I was feeling the baby kick.
I can certainly understand why female physicians wait so long to have kids. Residency is really hard as is and it seems like you've got to be out of your freaking mind to get pregnant during that time. But I saw my mother struggle unsuccessfully with infertility in her late thirties, so for me, waiting wasn't something I felt comfortable doing.
In less than a month, a new crop of residents will be graduating. I see a lot of the female graduating residents have little baby bulges and I admit I feel a little jealous that they managed to somehow stave off the baby fever through residency... and now they get the luxury of working a cushy part time job while taking care of their baby (or so I'd imagine in my jealous little fantasy). I wish I could do that, instead of doing my double baby/hospital calls.
But I'm happy with my choice too.