This resource assists primary care clinicians in monitoring for appropriate nutrition in premature infants after discharged from care in the neonatal intensive care unit (NICU).

Energy

• 120-130 kcal/kg/day to grow 15-20 g/day as they catch up to term (potentially more for ELBW).
• The needs decrease as the infant nears 40 weeks gestational age, but the recommendations do not account for “catch up” growth for SGA preterm infants or infants with suboptimal weight gain in the NICU. [Martin: 2006] [Lapillonne: 2013]

Protein

• 2-3 g/kg/day – on the lower end closer to term, on the higher end when around 34 weeks GA. [Lapillonne: 2013]
• However, for ELBW infants, protein requirements are higher and range between 3.5-4.5 g/day. [Mehta: 2009]

Calcium

Iron

• 2-4 mg of elemental iron/kg/day – on the lower end for routine care of late preterm infants.
• Start around 4 weeks of life and continue until approximately 12 months of age or when the child can ingest adequate iron from food or formula. May require monitoring to adjust. [Lapillonne: 2013] There is a lack of consensus on this, however, and consideration must be given to use of iron-containing formulas, fortifiers, multivitamins with added iron, and foods as well as the history of erythrocyte transfusions, as premature infants may also develop iron overload. Common formulations for babies contain 15 mg of elemental iron per 1 mL of liquid. Iron supplementation can cause gastric upset and hard or darkened stools.

Lipids

Vitamin D

• Supplementation is recommended for all infants to help with bone development and other aspects of immune function and development. Typical daily dosing is 400 IU enterally. The Vitamin D3 formulation, cholecalciferol, tends to have more predictable enteral absorption than Vitamin D2, ergocalciferol. Even when a breastfeeding mother supplements her Vitamin D, the levels in breast milk do not meet the recommended daily requirements. Formula-fed babies need to drink at least 34 ounces (1 liter) of formula daily to obtain the recommended daily allowance of Vitamin D. Common formulations of Vitamin D3 for babies contain either 400 IU per 1 mL or 400 IU per drop. Side effects are uncommon; however, some infants find the supplement unpalatable. Please see Calcium and Vitamin D for further information about recommended intakes.

Typically, 150-200 ml/kg/day for infants taking 20 kcal/kg/day, may be decreased for infants taking increased caloric density breast milk or formula or with certain medical conditions requiring volume restriction. [Lapillonne: 2013]

Breast Milk

Formulas

The number of formulas approximating breast milk has increased over several decades. Specialized formulas are created for preterm infants to match changing requirements and respond to the increase in knowledge of the needs of the preterm infant. At the time of discharge from the NICU, formula-fed preterm infants may continue to require added nutrition to catch up to term weight and address their specialized nutritional needs. Preterm formulas developed for after-hospital care include 22 kcal/30 ml formulations, such as Similac Neosure Advance and Enfacare Lipil, and should be considered particularly for infants with birth weights <1500g for 9-12 months. See Formulas and Fortifiers for Premature and Low Birth Weight Infants ( 94 KB).

In addition to assessing the infant’s measurements for appropriate growth (see Missing issue with id: 44010697.xml), selective monitoring of blood urea nitrogen, complete blood count with ferritin or reticulocyte hemoglobin, protein markers such as retinol-binding protein* and/or prealbumin, alkaline phosphatase, and/or Vitamin D 25-OH may be valuable in determining the nutritional status of high-risk infants. [Lapillonne: 2013]

*Like prealbumin, retinol-binding protein is a marker of protein stores; its deficiency may also reflect an inflammatory state or Vitamin A deficiency.