Challenges in providing adequate and reliable nutrition for extremely low birth weight infants.

Background: There is limited data on macronutrient content and its variability in mothers' milk of extremely low birth weight (ELBW) infants. The primary objectives were to determine the mean and the range of macronutrient content in milk from mothers of ELBW infants.

Methods: A near-infrared milk analyzer was used to measure fat, protein and carbohydrate. Data is presented as mean ± SD, median, and minimum/maximum values. Intraclass correlation coefficients (ICC) and linear regression were used to examine differences between repeat analyses.

Results: The mean GA and BW of infants were 25.6 ± 1.9 weeks and 678.6 ± 78.6 g respectively. The mean caloric content of 212 milk samples (10 infants) was 20.1 ± 5.4 cals/oz. The mean fat, protein and carbohydrate content were 3.2 ± 1.8, 1.6 ± 0.5 g% and 8.0 ± 0.8 g% respectively. Large subject to subject and day to day variations were observed. The range of calories, fat, protein and carbohydrate content were 10.4-42.3 cals/oz, 0.2-14.1, 0.6-3.3 and 6.4-13.7 g% respectively. Nearly half of all samples had 17 or less cals/oz and 10% had 15 or less cals/oz. There were no significant differences between repeat readings on a single sample.

Conclusions: Standard fortification in presence of significant variation in macronutrient and caloric content of mother's milk can lead to large day to day variation in macronutrient and caloric intake of ELBW infants. Clinical significance of variable intake from one day to another in infants at high risk of NEC and growth failure is unclear and needs further study.