The development of microcephaly after hypoxic-ischemic cerebral injury in the full-term newborn was studied at the University of British Columbia, Vancouver, Canada. Serial head circumference measurements obtained at 4, 8, and 18 months of age in 54 newborns suffering from acute, hypoxic-ischemic encephalopathy showed that a decrease in head circumference ratios of >3.1% between birth and 4 months of age was highly predictive of the development of microcephaly before 18 months. Head circumference ratios were actual head circumference/mean head circumference x 100%. They were correlated with severity of neonatal HIE and outcome at 18 months. 
COMMENT. A decreased rate of head growth in the first 4 months after acute, intrapartum HIE correlates with the later development of microcephaly and neurological sequelae in the full-term neonate as well as very low birth weight infants.