Aspies For Freedom

Oxygen Deprivation May Contribute to Autism

By Randy Dotinga
HealthDay News

MONDAY, Dec. 19 (HealthDay News) -- New research with rats suggests that oxygen deprivation during birth could be a contributing cause of autism.

There's no easy way to test the oxygen-deprivation theory in humans, and the finding isn't likely to lead to better treatments in the near future. Still, the research gives scientists greater insight into how factors other than genetics may play a role in autism, said Fabrizio Strata, a neuroscience researcher at the University of California, San Francisco and co-author of the study.

Symptoms of autism, the most common condition in a group of developmental disorders known as autism spectrum disorders, can range from mild to severe. The disability usually strikes by age 3. It lasts a lifetime, and there is no cure, although some people with autism can learn to function well.

According to the U.S. Centers for Disease Control and Prevention, autism is characterized by three distinctive behaviors. Autistic children have difficulties with social interaction, display problems with verbal and nonverbal communication, and exhibit repetitive behaviors or narrow, obsessive interests. Scientists are not certain what causes autism, but it is likely that both genetics and environment play a role.

For reasons that aren't clear, autism seems to have become more common in recent years. One hotly debated theory suggests that vaccines are responsible, although some studies have failed to find a link.

Oxygen deprivation during birth is considered one possible cause because it can lead to brain damage.

By boosting the level of nitrogen in the air, Strata and colleagues deprived rat pups of normal levels of oxygen for as long as 10 to 12 minutes during birth. When the rats grew older, they displayed symptoms similar to those found in autistic children. It took longer for the rats to respond to some sounds, for example, and the brain regions that handle sound were disrupted.

Why would a baby be oxygen-deprived in the first place? According to Strata, a complicated labor can cut off a newborn's oxygen supply, as can a twisted umbilical cord.

Andy Shih, chief science officer with the National Alliance for Autism Research, said the oxygen-deprivation study presents an "interesting hypothesis," although the research hasn't been confirmed in humans.

It's possible that future research could lead to changes in obstetric practices to minimize the chance that babies will go without oxygen, Shih said. But "we're far away from that at this point."

The study findings appear in the Dec. 19-24 issue of the Proceedings of the  National Academy of Sciences.

Oh good, so it isn't mercury poisoning after all, I can stop the chelation now :roll:

One question that occurred while reading though: many autistics have a larger than usual brain size.  How would oxygen deprivation cause that?  

Alison

I can see it now "Timmy don't cold your breath like that or you'll become autistic!".

That is quite interesting.. My mom told me that I got stuck as I was bring born, that I was briefly deprived of oxygen, and they had to do an emergency c-section.

Most people in my dad's side of the family are engineers. Most of them don't have the best social skills, either. I wouldn't say they have full-blown AS, but they have kind of a similar personality & mindset.

So it would make sense that I have a genetic predisposition for AS, which was "activated" by my oxygen deprivation.

Hee, it was only when I was re-reading this later that I realised - perhaps the large head size causes the oxygen deprivation because the baby gets stuck!

Alison (ouch!)

As there  is as yet no  biomedical test for autism, which remains defined by a loose set of behaviours - the Triad of Impairments - it can be argued (and is) that there could be any number of different causes acting alone or in combination which lead to autistic outcomes - pre-natal anoxia, heavy metal poisoning, familial alcoholism, genes and chromosomes, foetal testosterone, and even the outmoded Refrigerator Mother of Freudian mythology.

Should this matter to us? We must live our lives as best we can no matter how we came into being as we are.

Stella

Well, I know i had major issues at birth. It ended up a protracted birth, inhaled stuff I shouldn't have inside the womb, ended up having to have my stomach pumped, and my heart also stopped. So yeah I'd say I was deprived of oxygen for a while :roll:

Yeah both my sons had too large of head to fit down the birth canal, eneded up with a c-section with both, my oldest was born after 72 hrs labor (12 induced) and then an emergency c-section due to fetal distress and had "transient" newborn apnea which had him in the NICU from 4-7 days old. But where there seems to be a genetic link in the family, not sure if much of the birth circumstances around Dylan would have contributed. I would rather focus on the future and making it the best for me and my children.

It's possible that part of the approx. 10% estimated autism not caused by genetic factors ( approx. 90% being caused by genetic factors) are caused by oxygen deprivation.

I have spoken to some parents whose children were premature and had oxygen deprivation, and have comorbids such as epilepsy too, and some have CP, as well as having an autism diagnosis.

...

I can see why some of us would not want to believe in this.  It would mean some of are damaged and not just different.

I still think it's often a combination of factors. I was deprived of oxygen during birth and was diagnosed with ADHD in childhood. Later (after '96) I got the Asperger's diagnosis. I somehow think it's also a genetic predisposition because my father also has a few AS traits.

I was not oxygen deprived at birth, neither was my son. We are both on the spectrum.
My daughter WAS oxygen deprived at birth, and is NOT on the spectrum. She has some aspie traits.

My daughter was oxygen deprived a short time after birth.  They had to hook her up to machines to save her life.  So there may be a connection with her autism.

Lauren was born after a very easy 8 hour labour and was delivered naturally.  My mum tells me that I was relatively easy and quick as well.  However my NT sister had to be turned in utero during mum's labour and was a bit "blue" (oxygen deficient) on delivery, as she suffered distress during the birth. So I have to agree with Amy that the majority of autism cases are due to genetics, with perhaps a few linked to environmental factors.

Alison