Tuesday, July 5, 2011
Uterine Environment and Autism
The second was the results of two new studies that were published in the Archives of General Psychiatry. One of them stated that environmental factors during pregnancy might contribute as much as genetics in the development of autism spectrum disorders. The 2nd study conducted by Kaiser Permanente Northern California found a 3 times higher risk of autism if the mother took antidepressants in the first trimester of pregnancy.
With the incidence of autism disorders increasing over time to the current range of 3-6 per 1,000 births, these studies are of interest to millions of parents and professionals. Autism affects boys at a rate of three times more than girls, and is usually detected by the age of 3. The cause has been maddeningly unknown.
While genes certainly play a part (as they do in most every disorder) other theories and assertions have been dis proven. It certainly does not have anything to do with "poor mothering" or "lack of maternal bonding". Those theories did more harm than bloodletting in the 19th century! The link between autism and vaccines has been thoroughly debunked. If you believe in science and research, you must believe that vaccines are not the cause and finally leave that one in the dust.
This new study looked at 192 pairs of identical and fraternal twins. One of the twins in each pair had classic autism. Some of the other twin sibs also had classic autism or Asperger's syndrome, a mild disorder in the autism spectrum.
(sidebar: Rent "Temple Grandin", a great movie that shows a super high functioning autistic woman who changed the world of animal husbandry)
The study found that autism spectrum disorders occurred in both twins in 77% of the male identical twins and in 50% of the female identical twins. Since identical twins share the exact same DNA and genes, you would expect a 100% autism rate in identical twins. The rate was even lower in fraternal twins. (who are like any other brother and sister sibling). The rates of autism in non-twin brothers and sisters is even lower still, suggesting conditions that the twins shared in the womb played a role in developing autism.
The second study found an elevated risk of autism in children whose mother took SSRI antidepressants (Prozac, Zoloft, Celexa, Lexapro) during the year before delivery. Although the risk was low (2.3%), if a pregnant mom took antidepressants during the first trimester, the risk of autism was 3X higher than mothers who didn't take SSRIs.
So what does all of this mean? The studies do not tell us what intra-uterine factors might play a role in autism. It could be diet, infection, stress, differences in blood flow. It could be a number of different factors that just happen to come together at a certain developmental time. We just don't know. Presumably the uterine environment is the same for both twins and the mom is the same but we know twins do not develop exactly the same.
Scientific breakthroughs usually happen when a study helps us ask even more questions. These new studies give us clues and raise more questions.
As for Casey Anthony, she will have to live in her own hell.
Posted by Toni Brayer, MD at 10:02 PM