Hello, I probably dont have muc advice to give but i thought i would reply because i hate it when no one does!
So you actually had mrsa enter your bloodstream - not just a skin/wound infection?
If it is in the blood and you keep getting re occurences of it then it may well reach the foetus - but im fairly sure it does go away if it is treated correctly and no more occurences of it happen (showing treatment was successful). If you do have it forever i guess there is a posibility that it may enter the babies bloodstream via the placenta - but seeing as many diseases/infections dont (such as HIV - if all the precautions are taken) you would have thought that would be a general thing! But to be honest i only know about mrsa and am speculating the rest in relation to effects on the foetus.
I think to really get the advice you need - you should speak to your doctor and see if they even know! There doesnt seem to be much information on the subject unfortunately.
Hope all works out for you :)