Nutrition for a Preterm Baby in the NICU

For a time, healthcare providers will care for your baby in the neonatal intensive care unit (NICU). They will make sure your baby gets all the nutrition they need. This will help them grow. Below is a guide for what to expect. 

How a baby is fed in the NICU

There are several ways to feed a baby while they are in the NICU:

  • A healthcare provider may start to feed your baby through an IV (intravenous line). This is a thin tube that goes into the vein.

  • A tube may be used to send formula or breastmilk into your baby’s stomach. This is called a gavage feeding.

  • Your baby may be able to breastfeed or bottle-feed right away.

The best method depends on your baby’s health and gestational age. Your baby will likely be feeding from a breast or bottle before leaving the NICU to go home.

What a baby is fed in the NICU

  • Total parenteral nutrition (TPN). This is a liquid that has all the nutrition your baby needs. A baby gets this through a vein. Healthcare providers give TPN to most very early preemies. This is because their digestive systems are not yet mature. They can’t absorb enough nutrition through regular feedings.

  • Breastmilk. Your baby will get the best nutrition and protection from breastmilk. It can be given with a gavage feeding, at your breast, or with a bottle. Many preemies learn to breastfeed while in the NICU. Ask the NICU staff the best way to pump and store milk for your baby. For a preterm baby, the milk may be mixed with a protein and mineral supplement (fortifier). This is to help your baby's growth. Breastmilk benefits a preterm baby because it lowers the chance of infections and is easiest to digest. Many NICUs will give donor milk from a milk bank to very small preemies whose birth parents don't have enough milk yet.

  • Formula. Special formulas are made for the needs of preemies when human milk is not available. The NICU team will give this to your baby with a gavage feeding or a bottle if breastmilk is not an option.  

From TPN to full breastfeeding or bottle-feeding

If your baby started on TPN, moving to full breastfeeding or bottle-feeding may take  3 to 4 weeks. This depends on your baby’s gestational age. A baby is often able to start learning to feed from a breast or a bottle by 32 to 34 weeks gestation. To reach this goal, TPN is decreased. Gavage feeding will provide most of your baby's nutrition until they can fully feed by mouth.

Gavage feeding goes into the stomach rather than a vein. This is also called enteral nutrition. It starts with a small amount of milk or formula. As your baby grows stronger, the amount of breast or formula feedings is increased.

A baby who is not ready to take all their feedings by mouth can still have gavage feeding without TPN. In some cases, a baby who is having a health problem may need to go back to TPN for a time. Milk or formula feeding will be started again when the baby is ready.

Talk with the healthcare team

If you have questions or want to learn more about how your baby is fed in the NICU, talk with the NICU nurses. They are there to help you and your baby during this time.

Online Medical Reviewer: Donna Freeborn PhD CNM FNP
Online Medical Reviewer: Liora C Adler MD
Online Medical Reviewer: Stacey Wojcik MBA BSN RN
Date Last Reviewed: 12/1/2022
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