Time to reconsider the cause of encephalopathies

Papers pp 1549,1544

Neonatal encephalopathy is a significant problem. The United States collaborative perinatal project studied 39 000 infants born with birth weights greater than 2500 g and found that 70% of the infants who showed early neonatal depression and encephalopathy died or were disabled.1 For many years it was accepted that fetal asphyxia during labour was the major cause of both neonatal encephalopathy and cerebral palsy. However, the evidence for this is surprisingly thin. Diagnosis of cerebral hypoxia-ischaemia during labour is difficult and is usually inferred from non-specific signs, such as low Apgar scores or seizures observed after delivery. More precise assessment using specialist technologies like magnetic resonance is possible but not widely available,2 and a working diagnosis of hypoxic-ischaemic encephalopathy may sometimes be applied with less than irrefutable proof of its presence. Nevertheless, several large studies have been unable to show significant perinatal asphyxia in most children who develop cerebral palsy1; indeed, a growing number of …