Estimated nutritional intake based on the reference growth curves for extremely low birthweight infants

Although the optimal goal of extremely low birthweight (ELBW) infants has been debated, it can be argued that the best nutritional strategy for ELBW infants is one which achieves better growth while preventing neurological sequelae due to nutritional inadequacy, even if it does not mimic fetal growth. Our aim is to propose an advisable and practically feasible nutritional intake for ELBW infants.

We retrospectively investigated the nutritional intake in 16 ELBW infants (gestational age 26.7 weeks, birthweight 879.6 g), who exceeded the standard growth curves for Japanese infants of ELBW. We also analyzed the nutritional composition of human milk from 15 mothers delivering before term (PT milk) until the 12th week of lactation. The nutritional intake was calculated according to the composition of the parenteral and enteral regimen.

The infants tolerated more than 100 mL/kg per day of milk until the fourth week of life. An average weight gain of more than 15 g/kg per day was achieved by the sixth week. An advisable nutritional intake capable of sustaining ELBW infants in a stable growing phase was calculated as the sum of the mean plus 1SD of the daily nutritional intake.

To exceed the ordinary growth curves for ELBW Japanese infants, it was suggested that more than 100 mL milk/kg per day could be fed until the fourth week of life, while the advisable daily intake of nutrients after six weeks of life should be as follows: water 160 mL/kg, protein 3.2 g/kg, fat 7.4 g/kg, carbohydrate 12.8 g/kg, energy 544 kJ/kg, the following minerals in mg/kg: sodium 45, chloride 82, potassium 110, calcium 140, phosphorus 70, magnesium 11, zinc 0.5 and copper at 60 micrograms/kg. Further studies will be needed to confirm the safety and effectiveness of this advisable intake for ELBW infants.