Longitudinal head growth in developmentally normal preterm infants
R. D. Sheth, M. D. Mullett, J. B. Bodensteiner and G. R. Hobbs
Department of Pediatrics, West Virginia University Health Sciences Center, Morgantown, USA.
OBJECTIVE: To determine growth in head circumference from birth to 18
months of age in normal infants with low birth weight. METHODS: Healthy,
appropriate-for-gestational-age, singleton, white infants weighing less
than or equal to 2500 g at birth and with normal development at 18 months
of age were included in this study. Serial measurements of head
circumference (corrected for gestational age) from 450 eligible infants
were compared with reference data for head circumference. RESULTS:
Longitudinal measurements of head circumference for infants weighing more
than 1000 g at birth were similar to reference data for term infants. Head
measurements for infants weighing less than or equal to 1000 g at birth
were notably smaller than the measurements in the reference data. A cubic
spline curve drawn through the head circumference measurements between
birth and age 18 months (corrected for gestational age) for infants
weighing less than or equal to 1000 g at birth was significantly (P <
.001) below the curve for infants weighing more than 1000 g at birth. At
age 18 months, the mean difference in head circumference between the group
weighing less than or equal to 1000 g at birth and the weights in the
reference data was 1.6 cm (P < .01). (Data were analyzed with Wilcoxon's
signed rank test.) CONCLUSIONS: These data show that head circumference
grids are appropriate for observing head growth in infants with a birth
weight more than 1000 g. However, head circumference growth for normal
infants with birth weight less than or equal to 1000 g does not "catch up"
with that of larger premature infants or term infants.