A new study published online in Pediatrics, a journal of the American Academy of Pediatrics, suggests that we may be closer to finding the real cause of autism: neuro-developmental changes which babies undergo in utero when a mother has contracted influenza, had a prolonged fever, or used certain antibiotics during pregnancy.
This will come as good news and bad news. To those parents who are still afraid of the effects of immunizations on children, the study is good news. For mothers who are pregnant, the study might prove frightening, but it is important to realize that no study, including this new one, has found a definite cause of autism. Rather, the study simply gives medical professionals and parents a clearer picture of the cause of autism.
The researchers conclude that autism may start while a child is in utero. This conclusion supports my personal experience as a pediatrician. I have many children in my practice with autism and the majority of the mothers of these children have told me that they knew that something was different with their children right from birth. They couldn’t put their fingers on the difference, but intuitively, they knew something wasn’t right.
Animal studies over the years have suggested that brain changes occur in a growing fetus when a pregnant mother experiences an activation of her immune system. The most common reason for a mother’s immune system to be activated is when she has contracted an infection. The researchers of this new study sought to find out whether or not something(s) related to maternal infection while pregnant was related to the development of autism in their babies.
The study reviewed over 96,000 children to see if their mothers had experienced infections during or shortly after pregnancy, used antibiotics, or experienced fevers during pregnancy. Of the 96,000 children, 1%, or 976, were found to have autism. The researchers asked mothers the following types of questions about their pregnancies: were they sick, did they have a fever, how long did they have a fever, whether or not they used antibiotics, and if they were sick, specifically, what type of infection did they have. The data (all self-reported by mothers) was then analyzed to see if there were correlations between any of these factors and autism.
This type of study can only find associations but cannot conclude specific cause and effect because of limitations. It can, however, give us insight into what might be causing autism. Here’s what the study concluded:
“Overall, we found little evidence that various types of mild common infectious diseases or febrile episodes during pregnancy were associated with ASD/infantile autism. However, our data suggest that maternal influenza infection was associated with a twofold increased risk of infantile autism, prolonged episodes of fever caused a threefold increased risk of infantile autism, and use of various antibiotics during pregnancy were potential risk factors for ASD/infantile autism.”
Again, while we don’t have conclusive evidence, scientists suspect that autism begins during a mother’s pregnancy. The news is not to frighten pregnant mothers, but to encourage them to seek good medical care early in pregnancy. As a pediatrician, I encourage pregnant mothers to go to their regular doctor visits, take prenatal vitamins, avoid alcohol, take extra care to get enough rest, and avoid illness when possible. All pregnant mothers should talk with their doctor about getting the flu vaccine because influenza infection was identified in this study as a possible risk factor for the development of autism.
