Resuscitation at birth associated with low IQ score.

May 15, 2009

Infants resuscitated at birth are likelier to have lower IQ scores in childhood.

Infants who undergo resuscitation at birth are more likely to have a low IQ score later in childhood than those who do not, and resuscitated infants with asymptomatic encephalopathy account for a greater proportion of affected adults than those with encephalopathy, according to a study published online April 21 in The Lancet.

David E. Odd, MD, of the University of Bristol in the United Kingdom, and colleagues conducted a study of 11,482 infants, of whom 10,609 formed the reference group who did not have symptoms of encephalopathy, did not undergo resuscitation, and did not require further neonatal care; 815 who were resuscitated but were also asymptomatic for encephalopathy and needed no further neonatal care; and 58 who were resuscitated and also received neonatal care for encephalopathy.

Resuscitation was positively associated with an increased risk of low IQ score at the age of 8 years; while being asymptomatic for encephalopathy contributed 3.4% to the population attributable risk fraction of a low IQ score, and encephalopathy added 1.2% to the risk, the investigators found.

"These findings are consistent with a cerebral injury of sufficient severity to delay respiration, but insufficient to cause obvious symptoms of encephalopathy," the authors write. "Our results support the idea of a continuum of reproductive casualty.

Odd DE, Lewis G, Whitelaw A, et al. Resuscitation at birth and cognition at 8 years of age: a cohort study. The Lancet, Early Online Publication, 21 April 2009doi:10.1016/S0140-6736(09)60244-0.