I have blogged several times about Caroline Rodger’s idea that sonograms during pregnancy greatly increase the risk of autism in the fetus. Her idea is supported by several lines of evidence, as she explains in this talk.
A new study provides more evidence. It found a high concordance rate among fraternal twins. In the general population from which the new study was drawn (California), about 1 child in 100 has autism. But if you are an identical twin, and your co-twin has autism spectrum disorder, your chance of having the same diagnosis is about 70%. The crucial point of the study is that the concordance was also high for fraternal twins: about 40%. As one commenter put it, this result “puts a spotlight on pregnancy as a time when environmental factors might exert their effects”.
Another study found more risk of autism if the mom took an anti-depressant during pregnancy. This supports the idea that a bad prenatal environment causes autism.
Thanks to Paul Sas and Gary Wolf.
Twins are exposed to the same environmental factors even after pregnancy. They are fed the same foods, go out together, live in the same house, even go to pre-school together. The commentator completely ignores this.
These studies just point to the importance of epigenetics, nothing else.
I guess that ultrasound should remain potentially dangerous until proved safe.
More so when the current technology capabilities and accuracy are rather poor, only adding to the prenatal stress and the mother’s stress (“Madam, there is a 1 in X probability that your child will have XXX). Meanwhile, Michel Odent is a great source of information on pregnancy and birth-giving https://www.wombecology.com/maternalemotional.html
It seems to me that the figure for fraternal twins is useless for drawing conclusions about pregnancy unless we also know the figure for siblings gestated apart. Fraternal twins share half the genes, so the 40% correlation is what you would expect.
This study did not measure the concordance for siblings gestated apart. I think it’s about 10%.
If ultrasounds “cause autism” (per the title of your post), the difference between identical and fraternal twins would be negligible. The difference between 70% and 40% only suggests that ultrasounds may exacerbate a predisposition for autism.