A Longitudinal Study of the Growth of Low Birth Weight Infants

Physicians may need to consider the growth of children–especially those of unusual size for age–from two different viewpoints. Most pediatricians are used to thinking of what may be called distance growth: how "normal" is a child's actual length at 2 years? The other aspect, velocity growth, expresses the rate or speed at which the child has grown. This may be equal for children of corresponding ages, whereas their distance growth may vary greatly. Failure of growth at a normal rate in one child should be investigated whereas another child with horizontal growth measurement outside ± 2 SD, but with normal velocity growth may require no investigation. Data from this study provide not only mean measurements for weight, length, and head circumference of low birth weight infants who are grouped by sex and gestational age, but also provide velocity growth from birth through 3 years of age. Preterm infants (gestational age 37 weeks) had greater velocity growth rates than small-for-date infants (full-term, low birth weight). At 1, 2, and 3 years the SFD infants had the smallest mean measurements of all the study groups of low birth weight infants. Comparative full-term infants were larger than low birth weight infants from birth through 3 years of age.