In the womb, the nutritional needs of the fetus are met by the mother via the placenta and umbilical cord. Following birth, normally, a baby will begin feeding right away from the breast. For some premature babies, though, this may not be possible. Other methods of feeding the premature baby must be used until the baby can begin sucking, swallowing, and feeding on her own.
Although the gastrointestinal (GI) tract of the fetus is fully formed at about 20 weeks of gestation, it is not fully functional. All the basic parts such as the stomach and the small and large intestine are there, but some mechanisms needed for the GI tract to begin functioning have not yet developed. For example:
- Peristalsis, the normal intestinal contractions that propel food through the system, won't start working well until about the 29th week.
- Enzymes needed to digest milk and formula may not yet be produced in sufficient quantity to be effective.
- The coordination skills for sucking and swallowing are not usually present until about the 34th week.
Breastfeeding can also be interrupted or made more difficult by interventions for other problems. For example, breastfeeding a baby who is breathing with the aid of a ventilator is not possible.
In these cases, the premature baby may be fed in intermediate ways while she grows and develops and gets ready to move on to the breast.