Full-Term Small-for-Gestational-Age Newborns in the U.S.: Characteristics, Trends, and Morbidity

Abstract

Objectives

The magnitude, characteristics, and morbidity of term (≥37 weeks gestation) newborns that are small-for-gestational-age (SGA) in the U.S. are underexplored. We sought to examine characteristics and trends for SGA-coded term newborns in the U.S.

Methods

Data were obtained from the Nationwide Inpatient Sample, a nationally representative database of hospital stays in the U.S. from 2002 to 2011. Term, singleton newborns with SGA codes were identified and examined over the study period. Demographic characteristics were compared for term newborns according to presence of SGA codes using χ ² tests. Odds ratios (OR) were calculated to compare morbidities between the two groups, adjusting for relevant demographic and clinical variables.

Results

In 2011, 15 per 1000 term newborns in the U.S. were coded as SGA, a 29.9 % increase since 2002. Compared with other term newborns, SGA term newborns were significantly ( p < 0.05) more likely to be female, receive public insurance, and reside in lower income zip codes. Comorbidities, including perinatal complications, metabolic disorders, central nervous system diseases, infection, and neonatal abstinence syndrome were more common among SGA-coded term newborns. These newborns also had higher odds of in-hospital death (OR = 3.0 95 % confidence interval: 2.0, 4.4), longer mean length of stay (3.7 vs. 2.3 days, p <0.001), and higher mean hospital charges ($12,621 vs. $5012, p < 0.001).

Conclusions for practice

Term newborns coded as SGA have higher morbidity, mortality, and incur higher hospital charges than other term newborns. More research is needed to understand causes of SGA so its incidence and effects can be reduced.