The changing pattern of low birth weight in the United States--1970 to 1980
S. S. Kessel, J. Villar, H. W. Berendes and R. P. Nugent
Analysis of US Natality Statistics using a bivariate (birth
weight-gestational age) approach shows that trends among
term-low-birth-weight infants (less than or equal to 2,500 g; greater than
or equal to 37 weeks, term low birth weight) and preterm-low-birth-weight
infants (less than or equal to 2,500 g; less than 37 weeks, preterm low
birth weight) have different patterns over time and by race. Between 1970
and 1980 the incidence of preterm low birth weight for all races declined
7.1%, while the term-low-birth-weight incidence declined almost three times
as much (20.9%). The incidence of preterm low birth weight among white
infants, during the same period, declined 9.0% with the black
preterm-low-birth-weight rate declining by 5.8%. The term-low-birth-weight
incidence, however, was 24.6% lower among whites and 14.9% lower among
black term-low-birth-weight infants for the same period. The reduction in
the overall low-birth-weight incidence for both populations is principally
caused by reduction in the incidence of term-low-birth-weight infants.
Term- and preterm-low-birth-weight infants reflect different etiologic
insults and require different intervention strategies for prevention.
