Solid Evidence That Autism Starts Before Birth

Whether autism begins while a child is still developing in a mother’s womb, or whether something happens after a child is born that causes the neurodevelopment disorder, has been the subject of much debate. A recently published article in the Journal of the American Medical Association (JAMA) lends further weight to autism starting before a child is born.

Researchers under neuroscientist Eric Courchesne examined the postmortem brain tissue of 13 boys, aged 7 – 16 years old, seven of whom were autistic and six who were not. The autistic children had an average of 67 percent more neurons, a type of brain cell, and in a certain region of the brain, the prefrontal cortex, which processes complex behaviors including language, decision-making and social behaviors. Specifically, the autistic children had 1.94 billion neurons in their prefrontal cortex, versus 1.16 billion in a child who is not autistic. The brains of the autistic boys had 79 percent more neurons in the dorsolateral prefrontal cortex, which is linked with executive functioning, such as planning and reasoning. They also had 29 percent more neurons in the mesial prefrontal cortex, which is associated with emotions and social behaviors.

In other words, the parts of the brain in which the autistic children had a noticeably high number of neurons are associated with areas, such as language and social behaviors, that autistic individuals are challenged in, sometimes severely. As Dr. Max Wiznitzer, a neurologist and autism expert at the Rainbow Babies and Children’s Hospital in Cleveland, Ohio, comments,

“This is a good example where you have too much of a good thing, it can be bad for you.”

Dr. Wiznitzer provided this metaphor to explain:

He likens the brain to an assembly line with too many workers (brain cells) sitting around. And when you have too many workers on the line, they can interfere with one another rather than contribute to the factory’s (or brain’s) productivity. Wiznitzer agrees that even though this is a small study, it’s consistent with previous research.

Neurons, says Courchesne, are only generated during fetal development, and specifically between 10 and 20 weeks. The number of neurons a person has remains the same, but the neurons grow in size and form connections. After the second trimester, neurons are “pruned,” which is to say, they undergo “planned cell death.” As Lizabeth Romanski, an associate professor of neurobiology and anatomy at the University of Rochester Medical Center who did not participate in the study says, what needs to be found out now is “whether autistic brains generate more neurons, or if they have a malfunctioning ‘pruning’ process.”

Research offering proof that autism beginning before birth would help lay to rest heated debates about autism’s causes, such as that a vaccine or other external agent “makes”  a typically developing child “become” autistic.

Courchesne is a professor at the University of California San Diego School of Medicine and director of the Autism Center of Excellence. He says that the study provides some “really solid” evidence that autism has a prenatal origin.

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Photo of autistic child stacking cans (the author's autistic son used to stack cups over and over and over) by Andwhatsnext via Wikimedia Commons

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Terry V.
Terry V.2 years ago


Julie R.
Julie Rideout R.3 years ago

A government report published in 2003 acknowledges a DIRECT LINK between accines containing Thimerosal and neurological disorders in children. There is now little doubt. A tendency to be damaged by vaccines may be passed down genetically, but the real damage is caused by the ingredients in the vaccine.
Here is the study published at website:

"We were initially highly skeptical that differences in the concentrations of thimerosal in vaccines would have any effect on the incidence rate of neurodevelopmental disorders after childhood immunization. This study presents the first epidemiologic evidence, based upon tens of millions of doses of vaccine administered in the United States that associates increasing thimerosal from vaccines with neurodevelopmental disorders."

Learn more:

Andrea A.
Andrea A.3 years ago

Thanks for the info.

Shar F.
Sharon F.4 years ago

We need a healthy food supply. What are we waiting for?

Piinky J.
Piinky J.4 years ago

thanks for the article

Harold R.
Harold R.4 years ago

While the development of Autism is possible during pregnancy, this study does not prove it. Far more likely, is that it develops in the early years of life and this will depend upon the adequacy of the child's food consumption. Autistic children are low or lacking up to sixty nutrients including choline, cholesterol, amino acids, vitamins, minerals, and very importantly fatty acids. A picky eater will not consume an adequate diet and as the diet becomes more and more marginal it can lead to these disorders or even regression. Recent studies have shown that even non-verbal children benefit if the deficiencies are eliminated. It is interesting to note that none of the previous comments even mention the effect that diet can have on developing these symptoms. My recent studies confirmed that more than 90% of the respondents were generally lacking the animal source foods that could deliver the needed nutrition.

Patricia Abbott
Patricia Abbott4 years ago

I've long believed that there was an interuterine factor in autism. Given the study showing that virtually all pregnant women and their fetuses have harmful chemicals in their blood:

These chemicals that were tested for and found in pregnant women included:

PCB’s (polychlorinated biphenyls): This chemical was found in 99-100 percent of the women tested. Chemical that is prohibited and has been linked to cancer. Found in fish, meat and dairy products.
Organochlorine pesticides: Found in almost all of the women tested.
Polybrominated diphenyl ethers: Found in flame retardants, foam furniture
Phthalates: This chemical was found in almost all of the women tested. Found in beauty products, including some soaps, lotions and makeup. Shown to cause hormone disruption.
Perfluorinated compounds
Phenols: Chemical used in disinfectants.
Polycyclic aromatic hydrocarbons: Chemical found in burning fuel (such as car pollution). Also found in meat cooked at high temperatures, such as grilling or barbecuing -- and in smoked fish.
Perchlorate: Found in some drinking water
Bisphenol A: Chemical in canned goods, food packaging and plastics was found in 96% of the women tested. This has been linked to issues with brain development, as well as other health problems.
DDT: Pesticide that has been banned in the US since 1972 was found in almost all of the women.

Another study showed that GMO chemicals (from corn metabolites - The Bt GMO toxins, 3-MPPA and Cry1Ab) show up in mot

patricia A.
Pat A.4 years ago

Fascinating. Mind you, for all of those who want everyone to be 'normal' - we would lose quite a lot of geniuses and super geniuses that way. There is evidence that Isaac Newton had considerable problems - and only laughed once in his life - but the world would be so much poorer had he not existed.

Kate Goldfield
Kate Goldfield4 years ago

This is very interesting. I think it is by far the most solid evidence that we have so far of autism having prenatal origins. You would think that having more neurons would be a good thing, but if they all get tangled up and increase sensory input, and make it harder for the brain to sort all the information coming in because there is SIMPLY TOO MUCH INFORMATION COMING IN (which is how I feel as an adult with Asperger's), then I guess it could make sense why it would be a bad thing. If anyone is looking for Asperger's or autism resources, this is a good site that I found . I hope they do more research to confirm and further explain this theory.

Cathy C.
Cathy C.4 years ago

Good to know.