Feeding is the way in which a premature baby increases their size. This is important because in general the larger a baby is, the healthier they will be. A growing premature baby is usually a baby who is thriving and getting stronger and healthier day by day. This section will address the different methods of feeding premature babies, which are devised to maximize their growth and health. This section will also address the complications that can interfere with the various feeding methods and growth.
The goal of feeding a premature baby is to approximate the growth and weight gain that the baby would have experienced in the womb, in the third trimester of pregnancy. Head size should also increase with the size of the baby; the size of the brain has a corresponding increase. In general, premature babies should increase their length by 1 cm per week; should increase their head circumference by 0.7 cm per week; and should gain about 15 g per day in overall weight. Premature babies are measured and weighed to assess how much they are growing and therefore how well they are absorbing the nutrition.
Unlike some other procedures in the Neonatal Intensive Care Unit (NICU), feeding is often something in which parents can participate. No matter which method is used to feed the baby, there is likely a way that parents, and mothers when it comes to breastfeeding, can help. Many NICUs will encourage parents in this manner since it promotes bonding and indeed the baby’s health.
Along with certain types of food, there are several ways in which a premature baby can be fed. The type of food and the method used to deliver it will depend on the circumstances of the baby and, in some cases, the mother of the baby.
Gavage or tube feeding
Because babies younger than a gestational age of 34 weeks do not usually have the coordination to suck and swallow, they must be fed by some means other than the breast. Premature babies are almost always given a “nasogastric” or NG tube immediately following birth. This is a thin tube running from the baby’s nose to their stomach. Depending on the condition of the baby, feedings may not start for 24 hours and will always begin slowly with small amounts of breast milk increased over time. If the baby’s mother is already pumping milk, this can be poured into the feeding tube. If not, formula will be given in the same manner. As soon as a baby has developed the coordination necessary for breast feeding, they will be encouraged to do so.
Intravenous feeding
Babies whose gastrointestinal (GI) tract is too immature to absorb nutrition properly, or who have a complication that makes GI tract feeding impossible, are fed intravenously. This is called parenteral feeding. These babies are fed a nutritious substance called total parenteral nutrition or TPN. This feeding method bypasses the GI tract completely, giving the baby’s digestive system time to mature or heal. How long a baby receives TPN depends on how soon they can tolerate feeding through their GI tract.
TPN is made up of a glucose and amino acid solution with electrolytes, minerals, vitamins, and fats. It provides what a baby needs to grow and become healthy while breastfeeding, formula feeding, or tube feeding remains impossible. As soon as a baby can be fed using their GI tract, an effort will be made to do so. Even when the baby is being fed intravenously, small amounts of formula or milk may be given at intervals through a feeding tube to stimulate the functioning of the GI tract, essentially priming the baby’s digestive system for the future.
Immature gastrointestinal tract
If a baby’s gastrointestinal (GI) tract is immature, they will have to be fed a nutritious substance called total parenteral nutrition (TPN) intravenously. This method of feeding sends nutrition directly to the bloodstream, bypassing the GI tract. Parenteral feeding provides a similar amount of nutrition that the baby would have received in the womb, and gives the GI tract time to mature.
Although TPN is designed to provide similar nutrition to what the baby would have received in the womb and contains what a baby needs to grow, there can be complications from its prolonged use. First, whenever an artificial opening is created in the baby’s body, in this case an IV line through the skin, the possibility of infection is increased. Babies being fed in this way will be monitored for infection and given antibiotics if infection is suspected or detected.
Second, depending on a baby’s condition in terms of complications not directly related to digestion, there may be components of TPN that need to be adjusted. For example, some premature babies are at risk for hyperglycemia, which is an elevated blood sugar level.
Additionally, a baby’s liver function may not be optimal and they may have elevated levels of a substance called triglyceride. If this happens, it indicates that the baby’s body is not breaking down fats properly.
Moreover, prolonged use of TPN puts babies at risk for cholestasis, a condition affecting the flow of bile from the liver. Cholestasis can lead to jaundice.
All babies being fed TPN will be monitored and will have frequent metabolic tests performed with an eye to spotting these and other metabolic complications. Adjustments to the composition of TPN may be necessary. Additionally, small enteral feedings may be given in an attempt to stimulate proper metabolic function.
Feeding intolerance
Premature babies who are using their GI tract to absorb nutrition can have several different complications leading to feeding intolerance. Feeding intolerance is when a baby has trouble either keeping the milk or formula down, or digesting the nutrition. Problems with digestion are often first noticed if a baby has frequent diarrhea.
There can be several reasons for feeding intolerance. When babies begin feeding through a tube, it is done slowly with very small amounts given initially. As amounts are slowly increased, it is possible that the baby will be fed too quickly or more than they are able to handle at a given time.