Infants resuscitated at birth have an increased risk of a low IQ score, even if they remain healthy during the neonatal period

In an article entitled, "Resuscitation at birth and cognition at 8 years of age: a cohort study" published on May 9, 2009 by www.thelancet.com, the authors conclude that infants who were resuscitated at birth have an increased risk of a low IQ score, even if they remain healthy during the neonatal period (first two months of life).  David E. Odd, M.D., and colleagues aimed to determine whether infants receiving resuscitation after birth, but with no signs of encephalopathy, have reduced intelligence quotient (IQ) scores in childhood.

Three groups of infants were selected for the Avon Longitudinal Study of Parents and Children: infants who were resuscitated at birth but were asymptomatic for encephalopathy and had no further neonatal care; those who were resuscitated and had neonatal care for symptoms of encephalopathy, and the reference group who were not resuscitated, were asymptomatic for encephalopathy and had no further neonatal care.  Cognitive function was assessed at a mean age of 8.6 years, and a low IQ score was defined as less than 80.

IQ scores were obtained for 5,953 children with a shortened version of the Wechsler intelligence scale for children (WISC-III), the remaining 5,529 were non-responders.  In the main analysis at 8 years old, increased risk of a low IQ score was recorded in both resuscitated infants asymptomatic for encephalopathy adn those with symptoms of encephalopathy. 

Infants who were resuscitated had an increased risk of a low IQ score, even if they remained healthy during the neonatal period, the researchers said.  Resuscitated infants asymptomatic for encephalopathy might result in a larger proportion of adults with low IQs than do those who develop neurological symptoms consistent with encephalopathy.

Mild degrees of hypoxia or other damaging processes during birth might cause impaired cognitive function in later life.  Although severe perinatal cerebral insult often causes death or obvious physical impairments, such as cerebral palsy, hypoxia at birth can also cause subtle defects in cognitive function that are only detectable as the child grows older.  It was widely accepted that brain damage only occurs if the hypoxic injury causes symptoms consistent with encephalopathy during the neonatal period.  The authors refute this generally accepted premise.

The need for resuscitation at birth is a specific sign of delayed onset of respiration and may indicate recent brain injury, especially hypoxic ischemic encephalopathy.  Additionally, use of 100% oxygen at birth is associated with worse outcomes than the use of room air in infants who are resuscitated.

You should not assume that your child did not sustain a brain injury at birth simply because he/she shows no signs of encephalopathy during the first year of life.  Cognitive deficits may take time to develop with mild brian injuries and the delays associated with hypoxia at birth may not be clear until as late as 8 years of age.