Being born by Caesarian section may affect your intelligence

Researchers at the University of Bergen examined whether delivery method influences genetic factors affecting children's intelligence. The team, led by Dinka Smajlagic from the Center for Neuropsychiatric Disorders, analyzed the genomes of 2,421 children to identify potential interactions between genetic factors and delivery mode on intelligence development.

The strongest association found involved the GRIN2A gene, which encodes a glutamate receptor subunit. Glutamate is a neurotransmitter connected to neurodevelopmental disorders affecting intelligence. The study revealed that children born via Caesarian section with certain genetic variations in GRIN2A demonstrated lower IQ scores compared to those delivered vaginally.

Researchers attribute this partly to differences in microbial exposure. Vaginal delivery exposes infants to maternal gut flora, while Caesarian birth bypasses this exposure. "The method of delivery has been shown also to affect gut colonization and, thus, immunological development of a child. The microbiome content, in turn, may affect your behavior and brain function."

Data came from the Avon Longitudinal Study of Parents and Children (ALSPAC), which recruited over 14,000 pregnant women from Bristol, UK between 1991-1993. Intelligence was measured using the Wechsler Intelligence Scale for Children at age 8.5 years.

Smajlagic emphasized the study's limitations, noting findings are preliminary: "It's a relatively underpowered study, suggesting that individual common genetic variants may have gene x environment effects on intelligence."