EARLY PREDICTION OF THE DEVELOPMENT OF MICROCEPHALY AFTER HYPOXIC-ISCHEMIC ENCEPHALOPATHY IN THE FULL-TERM NEWBORN

The development of microcephaly after significant hypoxic-ischemic cer ebral injury in the fullterm newborn has major prognostic significance . However, the onset of microcephaly in this context may be delayed mo re than 12 months. Objectives. To determine whether serial head circum ference measurements and decreased rate of head growth in asphyxiated full-term newborns during the first few months of life may predict the development of eventual microcephaly. Methodology. Serial head circum ference measurements at 4, 8, and 18 months of age were obtained in 54 full-term newborns who had acute, hypoxic-ischemic encephalopathy. Th e rate of head growth was determined on the basis of changes in head c ircumference ratios which are calculated as follows: actual head circu mference/mean head circumference for age x 100%. Head circumference ra tios were correlated with severity of newborn encephalopathy and outco me at 18 months. Results. A decrease in head circumference ratios of > 3.1% between birth and 4 months of age was highly predictive of the ev entual development of microcephaly before 18 months (sensitivity 90%, specificity 85%). Conclusions. These data demonstrate that serial head circumference measurements during the first 4 months of life and calc ulation of decreased rate of head growth in full-term newborns with hy poxic-ischemic encephalopathy may predict microcephaly before its actu al occurrence.