Hi Kim
Welcome to Hip Talk.
There have been a few women that have had hip resurfacing and had normal babies afterwards. They have posted on the Yahoo Surface Hippy Group
http://groups.yahoo.com/group/surfacehippy/
I don't remember who they were, but if you join the group you might try to do a search about pregnancy and hip resurfacing. You could also post to see if any reading has had a baby and a hip resurfacing. I am sorry that I have not made a story about this, but don't always get to everyone that posts with an interesting story.
This group is still pretty small and I don't think you will find an answer from anyone on it. The metal ions are the highest in the first year as the new hip wears in, then after that I have read that it is no more than the chromium you get in a vitamin with mineral pill. It is very small.
Of course, I am not medically train, and certainly am not an expert. You should discuss this with your doctor and ask for more medical studies and information.
You are very young to consider having a THR. If you have a THR you would have to go to an old fashioned small ball plastic/metal one to get away from the metal ion issue or go to a ceramic on ceramic with a titanium stem. You can't go the MOM or metal on metal route because they are made of the same metal that the BHRs are. So you will have to be careful what you choose. You definitely don't want to go the small ball THR route or you could easily dislocate our hip just lifting your baby. You would at least need a ceramic on ceramic. The ceramic on ceramic used in the US is a smaller diameter than the ones used overseas. So you might want to check into that too.
I wish you the best of luck. Please let us know how else we can help.
Pat