Breast milk is rich in the nutrients that promote brain growth and nervous system development. Of course, it is also the perfect first food to help your human baby achieve every aspect of ideal growth and development.

The nutrient levels and the available calories are often adequate for "older" or "bigger" premature babies, and for many other high-risk babies. However, lower nutrient levels and the "full-term" calorie count in human milk may create problems for the low birthweight baby who weighed 3 pounds, 5 ounces (1,500 grams) or less at birth, or for babies with certain health conditions affecting digestion or the use of nutrients. These babies may not get enough of the minerals, such as calcium, phosphorous, and iron from their mothers' milk alone. They also may need additional calories.

Although your milk is best, it is not always complete with the nutritional needs of very small premature babies or some very sick newborns. Fortunately, adding to, or "fortifying," a mother's milk does not appear to diminish the nutritional and anti-infective benefits your baby will gain from receiving your milk, and may help to better provide the nutrition your baby needs

• nutrients - Several studies found more fat, protein, and the minerals sodium, chloride, and iron in "preterm milk" than in "term" milk. The variation in nutrient content seems to be of benefit for the preterm baby.

  Generally, premature babies who receive their own mothers' milk develop better eye function. They, and other high-risk babies fed mothers' milk, usually perform better on different kinds of intelligence tests as they grow older. This is mostly due to certain types of fats (fatty acid chains) in human milk, which are not available in artificial formulas. Yet these fats have been shown to be especially important for the growth and development of a high-risk baby's eyes, brain, and nervous system.

  During the last weeks of pregnancy, a baby builds a lot of body tissue. Because premature babies are born early, they must build this tissue after birth. Tissue building requires protein. Preterm milk has a bit more protein, and the protein is in a form that is more easily used by your premature baby. Other extra proteins in preterm milk reflect higher levels of certain anti-infective properties, especially ones that protect babies against gastrointestinal and respiratory infections.

• anti-infective properties - Only human milk is alive with many different kinds of disease-fighting factors that help prevent mild to severe infections in babies. Preterm milk has higher levels of these anti-infective properties. Antibodies in human milk directly protect against infection. Other anti-infective factors create an environment that is friendly to the "good" bacteria, referred to as "normal flora," and unfriendly to "bad" bacteria, viruses, or parasites. Human milk also appears to have properties that help a baby's own immune system work best. The anti-infective properties in mother's milk are especially beneficial for premature and other high-risk babies, since these babies are more likely to be exposed to, and pick up, infections more easily. Babies receiving their own mothers' milk are many times less likely to develop diarrhea and a severe intestinal illness called necrotizing enterocolitis (NEC) during their NICU stay. If any of these problems do occur, they are usually less severe for the baby receiving his own mother's milk. Babies that are fully, or almost-fully, breastfed and those receiving expressed breast milk also have significantly fewer GI, respiratory, ear, and urinary infections after hospital discharge.

• easily digested - Since nature designed human milk for human babies, your milk is the most easily digested food your baby can receive. A nutritious, yet easily digested first food is important for any baby, but it is particularly beneficial for the immature digestive tract of a premature baby and the more sensitive systems of many other high-risk babies. Your baby uses less energy, yet breaks your milk down more completely into its basic ingredients, so the nutrients, anti-infective factors, and all the other ingredients in your milk are more available to fuel your baby's body functions and to promote growth and development.

• bio-availability -Bio-availability refers to how well the body can use the nutrients in a food. The high bio-availability of nutrients in human milk means your baby gets more benefits from those nutrients. This is true even for nutrients that appear in lower levels in breast milk when compared to artificial formulas, because your baby's body can absorb and use them most effectively. It also means your baby saves the energy that would be needed to eliminate any nutrients he had difficulty digesting or using.

• suitability - Your milk is best suited to, and so it is more "gentle" on, your baby's body systems. The suitability of your milk plays a role in your milk's digestibility, and it allows your baby's body to function most efficiently while spending much less energy on body functions. Suitability is also thought to be one reason that babies receiving their own mothers' milk are less likely to develop allergic-related skin conditions.

  The digestibility, bio-availability, and suitability of your milk means your baby's body is able to work less yet receive more nourishment. This results in less stress for the baby's heart, lungs, bowels and kidneys, which allows your high-risk baby to use more energy to grow and get better. It often means the high-risk baby receiving mother's milk is ready for oral feedings earlier and can be discharged home sooner than high-risk babies receiving other types of feedings.