New Postnatal Growth Grids for Very Low Birth Weight Infants

Abstract

Objective. To generate contemporary postnatal growth curves for hospitalized very low birth weight infants. Design. Retrospective survey. Setting. Tertiary intensive care nursery. Patients. All surviving singleton, appropriate-for-gestational age infants with birth weight ≤1500 g, born January 1, 1987, to May 31, 1991, who did not develop necrotizing enterocolitis (N = 205). Measurements and results. Macronutrient intakes and body weights were recorded daily, with crown-heel length and occipital-frontal head circumference recorded weekly up to 105 days of age or hospital discharge, whichever occurred first. Growth curves were generated for four birth weight ranges: 501 through 750, 751 through 1000, 1001 through 1250, and 1251 through 1500 g. Compared to previously published growth curves, the current infants regained birth weight more quickly and exhibited larger average daily weight gains. These differences were most apparent in infants of lowest birth weight. Conclusions. The "premature growth grid" constructed by Dancis et al more than 40 years ago may no longer be a useful standard of early postnatal growth for present-day very low birth weight, appropriate-for-gestational-age infants. The new weight curves are a more accurate reflection of current in-hospital growth trends, especially for infants weighing ≤1000 g at birth.