Longitudinal Growth of Hospitalized Very Low Birth Weight Infants

ABSTRACT

PURPOSE: This study was performed to investigate the postnatal growth for very low birth weight infants (VLBWI) and to evaluate the factors associated with growth during initial hospitalization. METHODS: The subjects for the study included 155 infants, birth weight less than 1, 625 g, who were admitted to neonatal intensive care unit of Asan Medical Center from January of 1999 to May of 2002. Infants with twin or triplet, necrotizing enterocolitis, small for gestational age and congenital abnormality were excluded. Nutrient intakes and body weights were recorded daily during the first 8 days, 11th and 14th day and then weekly after the 14th day. Length and head circumference were measured weekly. All of the data was collected up to postnatal 105 days or hospital discharge. Enteral plus parenteral fluid, calory, and protein intake were evaluated daily. RESULTS: Growth curves were made according to four birth weight groups group of 750 g (625-874 g), 1, 000 g (875-1, 124 g), 1, 250 g (1, 125-1, 374 g), 1, 500 g (1, 375-1, 624 g), respectively. Mean fluid intake was 143.7 +/- 24.9 mL/kg/d, caloric intake was 78.1 +/- 10.5 kcal/kg/d and protein intake was 2.4 +/- 0.3 g/kg/d. The mean period to regain birth weight was 19.9 +/- 7.8 days and 25.4 +/-11.0, 22.2 +/- 7.5, 18.8+/- 7.3, 17.3 +/- 6.2 days were required, to regain birth weight for previously mentioned birth weight groups, respectively. Birth weight, gestational age, duration of total parenteral nutrition, age at starting of enteral feeding were negatively associated with the mean duration to regain birth weight. Duration of respiratory support and supplemental oxygen were negative predictors, unlike protein intake which revealed to be a positive predictor. CONCLUSION: Postnatal growth curves of VLBW infants were based on body weight, length, head circumference. Birth weight, gestational age, duration of total parenteral fluid, age at starting of enteral feeding were negatively associated with the mean duration to regain birth weight. There was a positive correlation with protein intake. More rapid regain to birth weight was associated with a shorter duration of respiratory support and supplemental oxygen.