University of Manitoba study questions FDA warning about anesthesia

The US Food and Drug Administration issued a warning in 2016 stating repeated or lengthy exposures to general anesthesia may harm brain development in children under 3. Children’s hospitals in Canada took issue with this warning, based partly on studies using the Early Development Instrument (EDI).

Research Summary

  • There was no association between receiving anesthesia before the age of 2 and child development, as measured by the EDI.
  • For children between 2 and 4, single exposure to anesthesia was associated with lower EDI scores. However, the authors questioned whether other factors were the cause.
  • Multiple exposures to anesthesia did not impact child development more than single exposure.

What is the research about?

Studies show that general anesthesia negatively impacts animals’ developing brains. Yet, the effect on children’s cognitive development is unclear.

Does exposure to general anesthesia before the age of 3 negatively impact development?  Is the number of exposures to general anesthesia more damaging than age of exposure? Or does general anesthesia have no effect on cognitive development?

A University of Manitoba study looked at how exposure to general anesthesia before age 4 affects child development.

What did the researchers do?

The study looked at 18,056 children in Manitoba.

  • 3,850 children were exposed to general anesthesia once
  • 620 were exposed more than once
  • 13,586 had no exposure

Researchers linked children’s health and social services records with their EDI data. The researchers tried to pin point the impact of anesthesia by taking into account:

  • Birth year
  • Sex
  • Mother’s age at birth of her first child
  • Income
  • Urban vs. rural

What did the researchers find?

Being exposed to anesthesia once between the ages of 2 and 4 years of age had a slight negative effect on early development. The effects were most noticeable in the Language and Cognitive Development and the Communications and General Knowledge domains.

However, exposure to anesthesia between birth and 2 years of age had no effect.

Being exposed to anesthesia more than once did not increase the risk of poorer development.

What does this research mean?

These findings show that general anesthesia exposure had no effect on children 2 years and younger, the period of brain development some believe to be most susceptible. These findings match those found in a 2016 study using EDI data.

Both studies were cited in a Globe and Mail article questioning the US Food and Drug Administration’s warning that exposure to anesthesia before the age of 3 may harm brain development.

The authors did find an impact when exposure to anesthesia occurred between 2 and 4 years of age. However, as earlier exposure did not impact child development and recent studies also failed to find an impact, the authors suggested this finding may have been due to an unknown confounding factor.