Gestational Age-Specific Growth Parameters for Infants Born at US Military Hospitals

Background.—Military hospitals currently use gestational age-specific growth curves based on data collected in Denver, Colo, from 1948 to 1961. A number of population and environmental factors and medical practice changes may make these curves nonrepresentative. Objective.—Determine if presently used growth curves represent norms for infants born in military hospitals and create new curves for use in military hospitals. Methods.—Data were collected from medical records of tertiary- and primary-care military hospitals. We created growth curves created for birth weight, length, and head circumference and compared these curves at gestational ages 23–42 weeks to previously published norms and to 1998 national vital statistics. Racial and ethnic differences between groups were compared. A retrospective analysis of blood-glucose measurements for healthy term infants was performed to identify potential safety issues. Results.—Significant increases in growth parameters were noted for infants born in military hospitals. Specific racial and ethnic groups within the military also had an increase when compared with these groups in the United States as a whole. Less than 1% of infants classified as large for gestational age (LGA) according by old standards but average for gestational age (AGA) according to new curves experienced hypoglycemia. Conclusion.—Published growth curves may not represent infants born in military hospitals. Term infants born in military hospitals as a group and in racial and ethnic subgroups are larger than term infants born in US civilian hospitals. Prospective use of curves will help to validate their long-term applicability in military and civilian nurseries.