Growth of Chicago-area infants, 1985 through 1987. Not what the reference curves predict. Pediatric Practice Research Group
H. J. Binns, Y. D. Senturia, S. LeBailly, M. Donovan and K. K. Christoffel
Department of Pediatrics, Children's Memorial Hospital, Northwestern University, Chicago, III, USA.
OBJECTIVE: To determine if the National Center for Health Statistics (NCHS)
growth curves (including 867 white infants, born between 1929 and 1975, in
the Yellow Springs, Ohio, area) reflect contemporary infant growth in
pediatric practices. DESIGN: Observational cohort study of healthy term
infants. Office personnel obtained standardized measurements at health
maintenance visits. SETTING: Ten pediatric community practices that were
members of the Chicago, III, area Pediatric Practice Research Group (PPRG).
METHODS: Measurements of 1574 PPRG infants, seen on at least 5 occasions
between 2 and 54 weeks of age, generated sex-specific growth curves using a
3-parameter mathematical model fitted to the serial data for each infant.
Values from the computed curves were compared with NCHS growth references
at 1, 3, 6, 9, and 12 months. The birth weights of PPRG and NCHS cohorts
were compared. RESULTS: Mean birth weight of PPRG infants was significantly
greater than a similar NCHS measure. Compared with the NCHS reference
curve, PPRG infants were heavier at 1, 3, and 6 months, longer on all
comparisons, and had greater head circumferences, particularly in the early
months of age. CONCLUSIONS: The NCHS growth curves do not accurately
reflect infant growth in this cohort. Nationally representative data are
needed to revise the NCHS growth curves.
