@ voxelectronica: Having a Caesarean section would not be an option for you?

I did practical studies with midwives for 6 weeks and saw 38 children born, two of them Caesarean sections. One was an emergency, and the other was planned, because it was known she could not survive a normal birth, hence the section was planned and done. It all went well.

As for the question itself: I might be old-fashioned, but having a child should imho not have to do anything with any purely BDSM issue. The idea horrifies me.
What if the couple breaks up? "Sorry, I only gave birth to you because my Dom wanted it, now heīs gone, and I donīt want you anymore, either?"

*shudders*

A child should be born to people who love each other, or to someone who wants it (even if the partnership does not work out in the long run).
The idea of using pregnancy as an instrument of power makes my flesh crawl.