Exposure to anesthesia during cesarean section delivery (C-section) doesn’t increase a child’s risk of learning disabilities down the road, according to a new report in the journal Anesthesia.

Concerns have been raised that such exposure could harm the brain, given that just one exposure to anesthetics can cause brain cell changes in fetal and newborn animals, Dr. Juraj Sprung of Mayo Clinic in Rochester, Minnesota and his colleagues write.

Earlier this year, Sprung and his team published research showing that a single exposure to anesthesia before the age of four didn’t increase a child’s risk of being diagnosed with learning disabilities before age 19, but that more frequent exposures did increase risk.

To look at the role of very early anesthesia, the researchers looked at the same group of 5,320 children born to mothers living in Olmsted County, Minnesota between 1976 and 1982. Within this group, 921 - about one in six - had been diagnosed with a learning disability.

There were 497 children born via C-section, with 193 of the mothers receiving general anesthesia, and 302 having regional anesthesia.

Among the rest of the children, who were delivered vaginally, the researchers found that 20.8% had learning disabilities. That compared to 19.4% of kids whose mothers had received general anesthesia during C-section delivery.

But the risk was actually significantly lower for children whose moms had C-sections under local anesthesia: 15.4% of them had learning disabilities.

Sprung calls the findings “intriguing” and “exciting,” but he cautions that parents should not be rushing to schedule C-section deliveries based on the results. He and his colleagues hypothesize that if the result is not just a statistical oddity, risk may be lower for children whose mothers undergo regional anesthesia for C-section because eliminating pain with this type of spinal block-which is much more thorough than the type of epidural used for vaginal deliveries-might prevent the release of stress hormones. Such hormones are known to have adverse effects on brain development, according to Sprung.

He and his colleagues are now looking at whether there are any differences in risks of learning disability among children born vaginally depending on whether or not their mothers had anesthesia.

SOURCE: Anesthesiology, August 2009.