Nourishing Your Premature Baby in the NICU

March 8, 2018
Chug-a by Hudsonthego available through CC BY 2.0


Advances in perinatal medicine have improved the survival of premature infants born as early as the 23rd week of pregnancy. Preemies weighing less than one pound often survive and even thrive in NICUs across this country.

The NICU course can be a long and painful journey for both preemies and their families. One of the greatest milestones these babies will achieve is to learn to feed and grow on their own. It’s important to understand that preterm infants will need to grow and develop at a proportionally faster rate than term infants. So they will require special nutrition to support faster weight gain and growth.

Total Parenteral Nutrition

During the third trimester of pregnancy, the mother passes vital nutrients from her body to that of her unborn baby. When babies are born prematurely, they miss the opportunity to absorb and store these nutrients.

The first two weeks of the preemie’s life are often the most difficult. At first, preemies may be fed an intravenous solution of protein, fat, and carbohydrates called Total Parenteral Nutrition or TPN. This solution will provide nutrients such as calcium, phosphorus, and iron to replace what the mother’s body was unable to pass to her baby. Because TPN is a solution, the amounts of these nutrients we can provide are limited. If you remember high school chemistry and the process of osmosis, you remember how elements will move from an area of higher concentration to an area of lesser concentration. Adding too much calcium, protein, or iron to a TPN solution will cause those nutrients to precipitate or fall out of solution. This means that only a small amount of what the preemie needs can be provided by the TPN.

The TPN is a lifesaving intervention that almost all preemies will need at some point. As with most medical interventions, there are limitations to TPN. Because of these limitations, the preferred way to feed the preemie is through the digestive tract.

Feeding an Immature Digestive Tract

Feeding the digestive tract is referred to as enteral nutrition. Unfortunately, the preemie digestive tract is not yet fully developed. Feeding the immature gut can cause bloating, distention, vomiting, and in severe cases Necrotizing Enterocolitis (NEC), a devastating diagnosis where the intestines and digestive tract becomes inflamed and tissue begins to die.

In recent years we have learned that one of the best medical interventions we can provide for the preemie is not a medicine at all, in the pharmacological sense of the word. Human milk has always been regarded as the best source of nutrition for all babies, and it’s even more important for the premature infant. Colostrum, the first milk produced after delivery, will provide live, protective properties that will “inoculate” the preemie gut. Even the tiniest babies can receive the benefit of the colostrum swabbed in their cheeks.1

In the NICU we consider this the baby’s first vaccine. Mother’s milk will protect the preemie from infections that are common in the NICU as well as protect him or her from NEC. Human milk has naturally occurring enzymes that break down the fat and protein in the milk. This allows the human milk to move through the preemie’s system much more quickly than infant formula. This ease of digestion will allow feedings to be progressed more quickly thus decreasing the reliance on TPN.


There is no doubt that breastmilk is the best source of nutrition for the premature baby. Unfortunately, it is not enough. The levels of protein, iron, calcium, phosphorus, and vitamin D found in human milk alone will not be adequate to make up for the deficits created by preterm birth. In order to meet these needs, the human milk must be fortified, adding calories and minerals.

Each NICU is different in how they choose to fortify human milk. Infant formula manufacturers have developed a new generation of human milk fortifiers designed to meet the needs of the preemie. These fortifiers will provide the additional nutrients required to promote growth and development. Breastmilk is easier to digest and will be given to the baby first. Once tolerance to the breastmilk has been shown, the fortifier can be added slowly.

Measuring Head Growth

The growth of your preemie will be followed closely by the NICU team. The head circumference and length measurements are important in determining if your baby is growing properly. One of the most sensitive measurements is the head circumference. Numerous studies have shown that preemies that experience head growth similar to in-utero growth are less likely to have poor outcomes.2 Poor head growth is directly related to cerebral palsy and developmental delay. Large amounts of protein and fat as well DHA (Docosahexaenoic Aid ) and ARA (Arachidonic Acid), both essential fatty acids important for brain development and immune function, are needed to promote better head growth. This is why fortification of human milk is important.

Preemies will need higher levels of nutrients to prevent deficiency for as long as 12 months. The more premature the baby, the longer supplementation will be needed. At home, you may be asked to provide bottle feedings of premature formula in addition to your breastmilk or to add a fortifier to your expressed breastmilk. Talk with your baby’s health care provider to determine the best supplementation for your baby.

Importance of Pumping

Remember that your breastmilk will help protect your baby from infection and NEC. Begin pumping as soon after delivery as you can. NICU staff can help you determine a routine to increase your supply and how best to store your milk. Because your baby did not receive the transfer of nutrients from your body, a little extra nutrition in the form of fortification will  be needed to promote catch-up growth. Human milk fortifiers are a safe and effective way to meet the needs of your growing preemie. Talk with your NICU team today about how you can provide your breastmilk for your baby.


About the author

Amy GatesAmy Gates, RD, CSP, LD is an Instructor at The Medical College of Georgia (MCG) School of Medicine in Augusta and a Lecturer for the MCG School of Nursing and Department of Nutrition. She is a Clinical Preceptor for the Augusta Area Dietetic Internship, and she has served as Preceptor and Co-Director of the MCG Neonatal Nutrition Fellowship. She is currently employed as a Neonatal Dietitian at the MCG Neonatal Intensive Care Unit and is a Certified Specialist in Pediatric Nutrition. Amy has served on the MCG Nutrition Committee as well as the Perinatal Centers Surveillance Clinics Committee in Macon, Georgia, and she is certified in Childhood, Adolescent, and Adult Weight Management by the Commission on Dietetic Registration.

Her research interests have included the safety of powdered infant formula and feeding strategies for neonates with oral-motor dysfunction. Amy is a member of the ADA, ASPEN, and other professional organizations. She authors the MCG Neonatal Nutrition Handbook, which is revised yearly, and is a co-author of a book chapter titled Trace Elements, Enteral and Parenteral in Nutrition for the Premature Infant. Amy earned her bachelor’s degree in Nutrition and Food Science from Jacksonville State University in Jacksonville, Alabama, and did her internship in Clinical Dietetics with the Augusta Area Dietetic Internship.


1Rodriguez, N. A., Meier, P. P., Groer, M. W., & Zeller, J. M. (2008). Oropharyngeal administration of colostrum to extremely low birth weight infants: Theoretical perspectives. Journal of Perinatology, 29, 1-7
2Ehrenkranz RA, et al. (2006). Growth in the neonatal intensive care unit influences neurodevelopmental and growth outcomes of extremely low birth weight infant. Pediatrics, 117,1253-61.