In-hospital growth of very low birth weight preterm infants : comparative effectiveness of two human milk fortifiers

Abstract

The protein content of the only human milk fortifier available in South Africa was increased in 2017. The Original fortifier (OF) and the Reformulated fortifier (RF) provided similar energy. This study aimed to prospectively compare in-hospital growth during the intermediate stage of nutrition support of very low birth weight (VLBW) preterm infants receiving human milk fortified with these two formulations in a tertiary South African hospital. Intake of VLBW infants receiving exclusively human milk plus one of two fortifiers (OF 0.2gprotein/g powder; RF 0.4gprotein/g powder) was calculated. Change in Z-scores (Fenton, 2013) from start to end of fortification of weight, length and head circumference (HC) for age was calculated as primary outcomes. Additionally, weight gain velocity (g/kg/d) and gain in length and HC (cm/wk) were calculated. Fifty eight infants (52% female; gestational age: 30±2wk; birth weight: 1215±187g) received OF (2016 to 2017) and 59 infants (56% female; gestational age: 29±2wk; birth weight 1202±167g) received RF (2017 to 2018) for 15 days. Protein intake of RF (3.7±0.4g/kg/d) was significantly higher (p<0.001) than of OF (3.4±0.2g/kg/d). Protein-to-energy ratio of RF (2.6±0.2) was significantly higher (p<0.001) than of OF (2.3±0.1g/100kcal). No adverse effects were noted. In both groups Z-scores of weight and length dropped; Z-scores for HC showed slight improvements. There were no significant differences between the two groups in terms of Z-scores, weight gain velocity, length gain or HC gain. Analysed human milk from preterm infants’ mothers’ protein levels was higher than published values. In-hospital growth was not statistically different between groups, even though calculated protein intake and protein-to-energy ratio were significantly higher in RF group.