Autism And Cesarean Section: Rest-Assured, No Causal Link Has Been Found

Could there be any connection between delivery modes and autism risk?

New findings published in JAMA Psychiatry investigated a potential link. While initial study results suggested that children born via C-section were 21 percent more likely to be diagnosed with autism spectrum disorder (ASD), the findings did not hold up further in an analysis with sibling pairs; this would suggest that the initial association was more likely due to certain unknown genetic and environmental factors rather than a causal relationship that researchers had formerly been looking for. 

Statistics show that about 1 in 68 children has been identified with an ASD, according to estimates from the Centers for Disease Control and Prevention's (CDC) Autism and Development Disabilities Monitoring (ADDM) Network. ASD is almost five times more common among boys (1 in 42) than girls (1 in 189) and occurs in individuals of all racial, ethnic and socioeconomic groups. The behavioral disorder has also been linked to numerous perinatal factors that could possibly be linked to cesarean deliveries.

For the study, researchers examined a potential association between modes of delivery, specifically zeroing in on C-sections and using data on ASD from the Swedish registry for live births from 1982 through 2010. The study group included nearly 2.7 million children, of whom 2.1 million (80.1 percent) were born by unassisted vaginal delivery, 164,305 (6.1 percent) by elective CS, 175,803 (6.5 percent) by emergency CS and 196,058 (7.3 percent) by assisted vaginal delivery. There were 28,290 children (1 percent) diagnosed with ASD.

The author's sibling control study involved 13,411 sibling pairs, with one ASD-affected sibling and one unaffected. From this sample, 2,555 pairs were also discordant on the method of delivery, with one born via unassisted vaginal delivery.

"Although the traditional cohort analysis revealed birth by CS to be associated with ASD, it is not necessarily a cause because the association could be due to residual confounding. ... Therefore, because the association between birth by CS and ASD did not persist in the sibling control analysis, we can conclude that there is no causal association," the study concluded, in a news release.

At this time, researchers believe that certain unknown genetic and enviornmental factors increase the risk of both CS and ASD. 

Autism can be difficult to initially diagnose and scientists are still learning just what causes this developmental disability. The diagnosis of an ASD now includes several conditions used to diagnose more specific yet related conditions, including the following: autistic disorder, pervasive developmental disorder not otherwise specified (PDD-NOS), and Asperger syndrome. These conditions are now all called autism spectrum disorder.

ASD typically begins before the age of three and for some more severe cases may occur in early infancy, when the child has difficulties making eye contact. However, for some, they may develop normally until around 18 to 24 months of age in which they stop gaining new skills or lose some they once had. For more information on symptoms, click here.

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