Oh, sorry, I think you misunderstand me, I wasn't referring to 'corrective' surgery or the like, but just finding out whether you're going to have a boy or a girl. I know it sounds like a silly question to ask, but then again, there have been other things that I've been wrong about. To me, it would seem like a prudent thing to do to find out the sex of your baby beforehand so you can refer to them by name, buy pink or blue clothing, etc. I know some Catholic parents prefer to leave it as a surprise until the actual birth, thinking it's somehow more traditional or natural. I've even seen some people claim it's the 'only' Catholic thing to do. Hence the question.
Edit: Upon further reflection, I can see that my original question is pretty poorly worded. Oh well. Sorry for any confusion.