Babies delivered in cesarean sections when the mother is under general anesthesia have a 60% higher risk of developing autism, with the anesthesia – not the C-section – being the risk factor, according to a new Israeli study.
The study also found that a newborn delivered by cesarean section with the mother under general anesthetic were 2.5 times as likely to develop autism classed as severe.
The study compared children born at Soroka Medical Center in Beersheba from 2009 to 2016, 347 of whom were eventually diagnosed with autism.
Another 117 of the children in the study were diagnosed with non-autism developmental delay, and 2,226 children had no developmental delay.
An analysis of the figures, which were supplied by the Negev Autism Center at Ben-Gurion University of the Negev, indicated that the 60% increased risk of autism only applied to the children who had been born via C-section to mothers under general anesthesia, and not to all the babies born via cesarean.
The researchers also investigated whether or not the reason for the C-section birth had any statistical relevance to the development of autism.
They compared emergency C-sections to scheduled C-sections. In both groups, the mothers were put under general anesthesia.
The comparison revealed a small discrepancy, with the emergency C-sections under general anesthesia increasing the risk of the babies developing autism by 54%, compared to scheduled C-sections under general anesthesia, which increased the risk of autism by 69%.
The researchers concluded that it was general anesthetic administered to the mother, rather than delivery complications, that increased the chances of the babies going on to develop autism.
Study director Dr. Idan Menashe of the Public Health Department at Ben-Gurion University of the Negev said that his team’s findings “show that exposure to general anesthesia during a cesarean section is apparently the fundamental factor that connects C-sections to autism.”
“We must remember that we are talking about a statistical link.
It doesn’t explain the mechanism [of how general anesthesia causes autism], and more studies are needed to probe this link,” Menashe explained. “Another one of our studies, which found a link between C-section births and severe autism, is a hint that the operation and the general anesthesia don’t cause autism but rather worsen the symptoms.”
Menashe also noted that two years ago, the U.S. Food and Drug Administration issued a warning based on studies of nonhuman mammals that showed that exposure to anesthesia led to cognitive development problems, and called to decrease the use of anesthesia.
While highlighting the potential association between C-sections under general anesthesia anesthetic and autism, the study suggested that “C-sections performed with other types of anesthesia such as epidural or spinal sedation are relatively safe,” said Menashe, who is also the scientific director of the National Autism Research Center at BGU.
Researchers also found that the reason for the C-section surgery, either by choice or because of pregnancy complications, did not influence the outcome.