Incidence and influencing factors of growth retardation in premature infants with extrauterine growth restriction under one year of corrected age

Abstract

Objective To investigate the incidence and influencing factors of growth retardation in premature infants with extrauterine growth restriction (EUGR) under one year of corrected age. Methods Ninety premature infants with EUGR who were discharged from July 2014 to December 2017 from the Neonatal Intensive Care Unit of Tai'an Central Hospital were selected. The infants were followed within one year of corrected age. Weight, height, and head circumference were measured, and data such as feeding, diseases, prealbumin, and zinc were collected. The incidence and influencing factors of growth retardation were analyzed. The t-test was used to compare the differences in maternal age, birth weight, weight at discharge, gestational age, hospitalization time, total enteral nutrition time, prealbumin, and zinc between children with and without growth retardation. The Chi-square test was used to compare the occurrence of twins, pregnancy induced hypertension syndrome, diabetes mellitus, premature rupture of membranes, intrauterine growth restriction (IUGR), asphyxia, cesarean section, neonatal respiratory distress syndrome (NRDS), bronchopulmonary dysplasia (BPD), necrotizing enterocolitis (NEC), invasive ventilator use, anemia, and infection, as well as the difference in feeding methods between children with and without growth retardation. Logistic regression analysis was used for identifying high risk factors for growth retardation. Results The follow-up time points were 1, 6, and 12 months of corrected age, at which 90, 86, and 70 cases were present. The incidence of growth retardation in preterm infants was 48.9% (44/90), 30.2% (26/86), and 17.1% (12/70) at 1, 6, and 12 months, respectively. The rates of IUGR, NRDS, BPD, and invasive ventilator use at 1 month were significantly higher in children with growth retardation than in those without (χ2=10.146, P=0.001; χ2=7.479, P=0.006; χ2=14.407, P<0.001; χ2=10.500, P=0.001). Birth weight, discharge weight, gestational age, and prealbumin decreased significantly (t=-4.945, P<0.001; t=-3.522, P=0.001; t=-2.047, P=0.044; t=-2.312, P=0.023), hospitalization time and total enteral nutrition time were significantly prolonged in children with growth retardation (t=3.797, P<0.001; t=2.840, P=0.006), and the feeding methods were significantly different between the two groups (χ2=7.060, P=0.029). Logistic regression analysis showed that growth retardation was significantly correlated with total enteral nutrition time (P=0.040), IUGR (P<0.001), and BPD (P=0.011). The rates of IUGR, NRDS, BPD, and invasive ventilator use at 6 months were significantly higher in children with growth retardation compared with those without (χ2=8.474, P=0.004; χ2=12.613, P<0.001; χ2=24.398, P<0.001; χ2=12.662, P<0.001). Birth weight, discharge weight, gestational age, and prealbumin decreased significantly (t=-5.849, P<0.001; t=-3.211, P=0.002; t=-3.405, P=0.001; t=-2.636, P=0.010), and hospitalization time and total enteral nutrition time were significantly prolonged in children with growth retardation (t=5.351, P<0.001; t=3.095, P=0.003). Logistic regression analysis showed that growth retardation was significantly correlated with birth weight (P=0.013), IUGR (P=0.001), and BPD (P=0.022). The rates of IUGR, NRDS, and BPD at 12 months were significantly higher in children with growth retardation compared with those without (χ2=4.050, P=0.044; χ2=5.737, P=0.017; χ2=8.393, P=0.004). Birth weight, gestational age, and prealbumin decreased significantly (t=-3.192, P=0.002; t=-2.271, P=0.026; t=-3.509, P=0.001), and hospitalization time was significantly prolonged in children with growth retardation (t=3.133, P=0.003). Logistic regression analysis showed that growth retardation was significantly correlated with IUGR (P=0.040) and BPD (P=0.003). Conclusion Premature infants with EUGR discharged from the neonatal intensive care unit are at high risk for growth retardation. IUGR and BPD are the persistent risk factors for growth retardation in preterm infants with EUGR. Key words: Preterm infant; Intrauterine growth restriction; Extrauterine growth restriction