C-section anesthesia doesn't increase risk of learning disabilities, new study says

From MedPage:

TORONTO -- Anesthesia during a cesarean delivery is not associated with an increased risk of learning disabilities compared with vaginal birth, researchers said.

The finding -- from a population-based birth cohort -- suggests that brief exposure to anesthetics during birth has no long-term neurodevelopmental consequences, according to Juraj Sprung, MD, PhD, of the Mayo Clinic, and colleagues.

Indeed, in an unexpected finding, regional anesthesia during cesarean was associated with a lower risk of learning disabilities compared with vaginal birth, Dr. Sprung and colleagues said in the August issue of Anesthesiology.

One possible explanation for that observation, they said, is that cesarean delivery with regional anesthesia "attenuates the neonatal stress response to vaginal delivery that in turn has significant effects on later neural development."

But Dr. Sprung and colleagues cautioned that more study is needed to confirm or refute the observation. He noted that the apparent protective effect could well be a marker for unknown factors that influence learning disabilities.

Even so, "it's reassuring that the anesthetics required for cesarean delivery do not appear to cause long-term brain problems," Dr. Sprung said in a statement.

The issue has been of concern, since animal studies have shown that anesthetics can cause degenerative changes when applied to the young brain.

In addition, the same researchers recently showed that repeated exposure to anesthesia and surgery before the age of 4 was associated with an increased risk of learning disabilities.

To clarify the issue, Dr. Sprung and colleagues turned to the educational and medical records of all children born to mothers residing in five townships of Olmsted County, Minn., from 1976 through 1982 and who were still in the community at age 5.

All told, the cohort consisted of 5,320 children, of whom 193 were delivered by cesarean under general anesthesia and 304 by cesarean under regional anesthesia.

Within the group, 921 children were diagnosed with a learning disability before the age of 19, the researchers found.

Among those delivered vaginally, the cumulative incidence of learning disabilities was 20.8%, compared with 19.4% for those whose mothers received general anesthesia for cesarean delivery and 15.4% for those whose mothers had a regional anesthetic for cesarean delivery.

In an unadjusted proportional hazard regression, the incidence of learning disabilities did not differ significantly across the three modes of delivery, the researchers said.

But the pairwise comparison of vaginal birth with cesarean delivery and regional anesthetic yielded a hazard ratio of 0.73, which was significant at P=0.046.

After adjusting for sex, birth weight, gestational age, exposure to anesthesia between birth and age 4, and maternal education, the pattern was similar -- little difference across all three modes, but a hazard ratio of 0.64 for the pairwise comparison of cesarean delivery and regional anesthetic with vaginal delivery.

The researcher noted that the study was retrospective, which has inherent limitations, and was unable to account for all possible confounders.

They added that the birth cohort included mainly Caucasian children, which may limit how widely the findings apply.

The study was supported by the Mayo Clinic and the NIH. The researchers did not report any conflicts.