Association of small-for-gestational-age status with mortality and morbidity in very preterm Chinese infants

Abstract

Background Very preterm infants born small for gestational age (SGA) are at risk for short- and long-term excess mortality and morbidity resulting from immaturity and deficient intrauterine growth. However, previous findings are inconclusive, and there is a paucity of contemporary data in Chinese population. Objectives To evaluate the excess risks of mortality and morbidity independently associated with SGA birth in very preterm (before 32 weeks of gestation) Chinese infants. Materials and Methods The study population included all very preterm infants admitted to the neonatal intensive care units (NICUs) in our hospital and our medical treatment partner hospitals during a 6-year period. The SGA group consisted of 615 SGA infants, and 1230 appropriate-for-gestation-age (AGA) infants were matched with GA and sex as controls at a ratio of 2:1. The associations between SGA birth and outcomes (in-hospital mortality and morbidity) were evaluated by using multivariate logistic regression analysis after adjustment for potential confounders. The CRIBII score was used to indicate admission illness severity, acting as a covariate in the multivariate analysis. Results The SGA group was associated with increased risks of mortality [odds ratio (OR) 2.12; 95% CI: 1.27–3.54] and BPD [OR 1.95; 95% CI: 1.58–2.41] compared to the AGA group. No significant incidences of respiratory distress syndrome (RDS), severe retinopathy of prematurity (sROP), severe intraventricular hemorrhage (sIVH), and necrotizing enterocolitis (NEC) were observed in the SGA group. Further GA-stratified subgroup analysis showed SGA status exhibited certain patterns of effects on mortality and morbidity in different GA ranges. Conclusions SGA status is associated with excess risks of neonatal mortality and BPD in very preterm infants, but the increased risks of mortality and morbidity are not homogeneous in different GA ranges. The contemporary data can help inform perinatal care decision-making and family counseling, particularly for very preterm SGA neonates.