Even though it appears that they were healthy in the neonatal period (28 days following birth), infants who were resuscitated are more likely to have a low intelligence quotient (IQ) when they reach the age of 8. Dr David Odd, Neonatal Intensive Care Unit, Southmead Hospital, Bristol, UK, and colleagues report their findings in an article published Online First and in a future edition of The Lancet.
The authors analyzed and assessed children enrolled in the Avon Longitudinal Study of Parents and Children all with an average age of 8.6 years, and with an IQ as low as 80. They evaluated three groups of children:
- 815 who were resuscitated at birth but showed no symptoms of neonatal encephalopathy (clinical signs of acute brain injury in the neonatal period, such as seizures and/or altered responsiveness and tone) and had no additional neonatal care.
- 58 who were resuscitated and who had neonatal care for symptoms of encephalopathy.
- 10,609 as the reference group, who were not resuscitated, asymptomatic for encephalopathy and received no further neonatal care.
Findings showed that the increased risk of low IQ was of 65 percent in resuscitated infants asymptomatic for encephalopathy. The risk was multiplied by six for children with symptoms of encephalopathy compared to the reference group. However, the researchers remark that infants who need resuscitation are generally asymptomatic for encephalopathy, and as a result the numbers of surviving asymptomatic children with a low IQ have a larger impact on society than that of symptomatic infants. The number of children with a low IQ score as a result of oxygen deficiency from resuscitation at birth was of 3.4 percent for asymptomatic children and of 1.2 percent for those who developed encephalopathy.
The authors write in conclusion: “Infants who needed resuscitation, even if they did not develop encephalopathy in the neonatal period, had a substantially increased risk of a low full-scale IQ score…The data suggest that mild perinatal physiological compromise might be sufficient to cause subtle neuronal or synaptic damage, and thereby affect cognition in childhood and potentially in adulthood.”
In a supplementary note, Professor Maureen Hack and Professor Eileen Stork, Rainbow Babies and Children’s Hospital, Case Western Reserve University, Cleveland, Ohio, USA, comment: “Assessment of a perinatal hypoxic event and its prognosis needs an objective measure other than the neonatal neurological presentation alone.” They mention that Dr Odd and his collaborators could find support for their findings with studies measuring biochemical markers of the level of metabolic acidosis (which specifies the severity of oxygen deficiency at birth), MRI, multi organ dysfunction, and other factors.
Written by Stephanie Brunner (B.A.)