0919 Neonatal resuscitation and cognition at 8 years of age

In an 8-year follow-up study that utilised data from a cohort of 14688 births in Bristol, UK, Odd and colleagues addressed the important question of neurodevelopmental outcome in infants who had been resuscitated at birth. Three groups of singletons born at ≥36 weeks were selected for analysis: those who had been resuscitated and required postnatal admission and care for encephalopathy (n=36), those who had been resuscitated but required no further care for encephalopathy (n=421), and normal controls who required neither resuscitation nor postnatal care for encephalopathy (n=4338). Cognition was measured by means of a shortened version of the Wechsler scale (WISC III) and was defined as a score of <80. Unadjusted analyses at 8 years of age showed abnormal results for both resuscitated groups vs controls (OR for resusc plus care 6.22; OR for resusc plus no care 1.65). However after adjustment for the non-representative sample sizes in the three groups it emerged that the resuscitation-plus-no-care group had a risk of 3.4% for cognitive impairment vs 1.2% for those who developed encephalopathy. While this counter-intuitive finding might be real and important, it would nevertheless be useful to have more data from representative samples on which to base a conclusion. Be that as it may, the authors explain the adjusted results by postulating that the milder group had watershed injury at birth from a partial insult while the more severe group had deeper injury that had perhaps persisted for longer. What is important to note is the comment regarding oxygen-based resuscitation i.e. the authors comment on the potential for oxygen to introduce free radical injury into the hypoxic-ischaemic equation, and acknowledge that this might be a confounder. However their next statement in the article is probably not fully reflective of current practice i.e. that whereas oxygen resuscitation was the standard of care at the time of enrolment into their cohort in the early 1990’s, the results might not be applicable today (implying that oxygen resuscitation today is more targeted and specific to neonates with an absolute oxygen requirement). Whether that is so would need to be tested in South Africa where it would appear that oxygen resuscitation is still the norm in many delivery units.

Read more:
Lancet 2009; 373: 1615-22
Arch Dis Child Fetal Neonatal Ed 2008; 93: F115-20