i'm not going to get into the vaccine debate at all, but we knew that there was something going on with charles LONG before he got the MMR vaccine. he was such a different baby in so many ways from the other two. i worried about him from very early on from a developmental standpoint. the other two had so many health problems, but we could tell that developmentally he was struggling early on. so, after the mmr vaccine (which as an RN and husband a dr. we have studied this extensively) we saw no change in how he acted. granted as he got older and the other two were doing more, we noticed more and more what he WASN'T doing, but we never saw any correlation between him pre and post mmr shot.

My advice (because you will get ALL SORTS of advice from whomever you ask... ) is to have a good heart to heart with your ped, assuming you really like and trust him/her. This is such a huge hot topic that most peds are ready to give you their 2 cents--whether they say what you want to hear or not, hopefully you have a relationship with your ped that helps you make this decision.
do your research, but both sides will really try to sway you in a very persuasive manner. use your common sense and go with input from someone (like your ped) that you trust.

good luck, hope this helps.

Meg