The relationship between head circumference and the development of communicating hydrocephalus in infants following intraventricular hemmorrhage.

Rapidly enlarging head circumference is a standard clinical sign of progressive hydrocephalus in an infant. Six neonates 29 to 36 weeks gestational age, with intraventricular hemorrhage, confirmed by ventricular tap, had head circumferences measured at intervals from birth. The sudden appearance of rapidly expanding head size, not associated with changing clinical status, occurred 9 to 20 days after the estimated time of hemorrhage in all of the infants. Air ventriculography within three days of abnormal acceleration of head circumference growth demonstrated moderately to severely dilated ventricles. The ventricles were probably enlarging slowing from the time of hemorrhage because there was no associated clinical deterioration in the infants coincident with the rapid increase in head circumference. After intraventricular hemorrhage, enlarging head circumference appears to be an insensitive sign of hydrocephalus in premature infants.