G.,
I have read into several of the studies and counter studies about the autism / MMR link. I think that it is either coincidental or there is a possibly a genetic factor in a very small percentage of children that react to the MMR - like an allergic reaction.
Some things to consider about those studies are...
The 1998 study only had 12 children in it - way too small to be conclusive. In addition, the researchers suggested that MMR vaccination caused bowel problems in the children, which then led to autism. However, in some of the children studied, symptoms of autism appeared before symptoms of bowel disease. In 2004, 10 of the 13 authors of the 1998 study changed their minds and said that MMR vaccine and autism aren't linked.
Other larger studies have found no relationship between MMR vaccine and autism. For example, researchers in the UK studied the records of 498 children with autism born between 1979 and 1998. They found that the percentage of children with autism who received MMR vaccine was the same as the percentage of unaffected children who received it. There was no difference in the age of diagnosis of autism in vaccinated and unvaccinated children.
I read another example in my Pediatrician's office where parts of the UK stopped giving the MMR for a while due to the studies that said they were linked to autism. Eventually, children started contracting the diseases the MMR is there to prevent and the impact was so great (greater than anything related to autism) that they started giving them again.
So even if MMR's did cause autism, the MMR is the lesser of the two evils and shouldn't be discontinued by the general public. If you have a strong family history of autism or Asperger syndrome, you may want to forgo the shots under the "possible hereditary allergy" theory and hope that because most people get the vaccines they won’t pass it to your child. Otherwise, your best bet in protecting your baby is to give them the shots.
FYI - If you do decide not to get the shots, most pediatricians and schools insist that it is an educated decision; so do a lot of homework, know the facts and make sure you are confident of your decision before you go to the pediatrician and refuse the shots or go to register your child for school.
Congrats on the new little one,
S.