Nature designed human milk especially for human babies. It is the ideal food for your baby. Your milk contains just the right balance of nutrients. It contains them in the form that is most easily used by the human baby's immature body systems. Because it was developed for your baby, your milk also is gentlest on your baby's. Your milk even changes along with your baby as he or she grows.
Mother's milk is rich in the nutrients that promote brain growth and nervous system development. It contains immune cells and other substances that prevent infection. Of course, human milk is also the perfect first food to help your human baby achieve every aspect of ideal growth and development.
The milk of mothers who give birth prematurely is somewhat different than milk produced by women after a full-term baby's birth in the following ways:
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. These fats are not as 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. Protein is needed to build tissue. Preterm milk has a bit more protein. Also, the protein is in a form that is more easily used by your premature baby. Other extra proteins in preterm milk have higher levels of certain anti-infective properties. This includes 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." These factors are also unfriendly to "bad" bacteria, viruses, or parasites. Human milk also appears to have properties that help a baby's own immune system develop and work best.
The anti-infective properties in mother's milk are especially good 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 during their neonatal intensive care unit stay. If any of these problems do happen, 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 breastmilk also have 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 good for the immature digestive tract of a premature baby and the more sensitive systems of many other high-risk babies. Your baby is able to break your milk down more completely into its basic parts, yet the process takes less energy than it would take to digest formula. 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.
Bioavailability. Bioavailability refers to how well the body can use the nutrients in a food. The high bioavailability 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 breastmilk when compared to artificial formulas (like iron) because your baby's body can soak them up and use them most effectively. It also means your baby saves the energy that would be needed to get rid of any nutrients he or she 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 allows your baby to digest and function most efficiently while spending much less energy on body functions. Suitability is also thought to be 1 reason that babies receiving their own mothers' milk are less likely to develop allergic-related skin conditions.
The digestibility, bioavailability, 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. It also allows your high-risk baby to use more energy to grow and get better. By providing human milk for your baby, you are creating a medicine that no hospital can make. Babies who receive this medicine are often ready for oral feedings earlier and can be discharged home sooner than high-risk babies receiving other types of feedings.