Head Growth and Developmental Outcome in Very Low-Birth-Weight Infants

Abstract

The predictive role of early head growth for subsequent outcome was evaluated in 85 infants with birth weight <1,500 g. On the basis of head circumference at birth and head growth between birth and age 6 weeks, infants were divided into four groups: (1) microcephalic at birth with less (< 3.5 cm) postnatal head growth (n = 9), (2) microcephalic at birth with more (≥3.5 cm) postnatal head growth (n = 12), (3) normocephalic at birth with less head growth (n = 32), and (4) normocephalic at birth with more head growth (n = 32). At both 6 and 15 months of age the two groups of infants with less postnatal head growth had an increased incidence of growth failure, whereas the two groups with more postnatal head growth had a low incidence, similar to that for a matched full-term group (n = 95). Major neurologic defects occurred significantly more frequently among infants who were microcephalic with less postnatal head growth; two thirds showed evidence of blindness, hydrocephalus, or spastic diplegia. This group also performed more poorly on the Bayley Scales than any of the other groups. Infants who were normocephalic with greater head growth were free of neurologic defects and had Bayley scores that did not differ from those for the healthy full-term infants. The two groups of infants with only one poor measure of head growth demonstrated intermediate scores at age 6 months. At age 15 months, the group with normocephaly and less postnatal head growth continued to have intermediate scores. The group with microcephaly and greater postnatal head growth, however, showed developmental catch-up; their scores did not differ from those of the group that was normocephalic with greater head growth or the full-term group. Less postnatal head growth was associated with an increased requirement for mechanical ventilation, patent ductus arteriosus, sepsis, delayed tolerance of feeding, and slower weight gain. These data suggest that early postnatal head growth may summarize the adverse effects of many perinatal risk factors and that head circumference at birth and head growth by six weeks are strong predictors of early developmental outcome in very low-birth-weight infants.