Premature Babies

Premature Babies

Premature infants, known as preemies, come into the world earlier than full-term infants. Prematurity occurs when a pregnancy lasts fewer than 37 weeks; full-term infants are born 38 to 42 weeks after the mother's last menstrual period (LMP).

There are many causes of preterm delivery. Sometimes it's caused by the mother's lifestyle choices during pregnancy: smoking, drinking alcohol, using drugs, eating poorly, not gaining enough weight, exposure to physical stress, and poor prenatal care are all causes of preterm delivery.

Often, however, the cause is not within the mother's control. The mother could have a hormone imbalance, a structural abnormality of the uterus, a chronic illness, an infection, or several other things that could lead to a premature birth. In addition, preterm delivery is more likely when a woman is over age 35, under age 19, or is carrying multiple fetuses. And sometimes the cause is simply unknown.

Premature infants have many special needs that make their care different from that of full-term infants, which is why they often begin their lives after delivery in a neonatal intensive care unit (NICU). The NICU is designed to provide an atmosphere that limits stress to the infant and meets basic needs of warmth, nutrition, and protection to assure proper growth and development.

Due to many recent advances, more than 90% of premature babies who weigh 800 grams or more (a little less than 2 pounds) survive. Those who weigh more than 500 grams (a little more than 1 pound) have a 40% to 50% chance of survival, although their chances of complications are greater.

A Preemie's Basic Needs

Warmth

Premature babies lack the body fat necessary to maintain their body temperature, even when swaddled with blankets. Therefore, incubators or radiant warmers are used to keep the babies warm. Incubators are made of transparent plastic, and they completely surround an infant to keep him or her warm, decrease the chance of infection, and limit water loss. Radiant warmers are electrically warmed beds open to the air. These are used when the medical staff needs frequent access to the baby for care.

Nutrition and Growth

Premature babies have special nutritional needs because they grow at a faster rate than full-term babies and their digestive systems are immature. Neonatologists (pediatricians who specialize in the care of newborns) measure their weight in grams, not pounds and ounces. Full-term babies usually weigh more than 2,500 grams (about 5 pounds, 8 ounces), whereas premature babies weigh anywhere from about 500 to 2,500 grams.

So, what are premature babies fed? Breast milk is an excellent source of nutrition, but premature infants are too immature to feed directly from the breast or bottle until they're 32 to 34 weeks gestational age. Most premature infants have to be fed slowly because of the risk of developing necrotizing enterocolitis (NEC), an intestinal infection unique to preemies. Breast milk can be pumped by the mother and fed to the premature baby through a tube that goes from the baby's nose or mouth into the stomach.

Breast milk has an advantage over formula because it contains proteins that help fight infection and promote growth. Special fortifiers may be added to breast milk (or to formula if breastfeeding isn't desired), because premature infants have higher vitamin and mineral needs than full-term infants. Nearly all premature babies receive additional calcium and phosphorus either by adding fortifier to breast milk or directly through special formulas for preemies. The baby's blood chemicals and minerals, such as blood glucose (sugar), salt, potassium, calcium, phosphate, and magnesium, are monitored regularly, and the baby's diet is adjusted to keep these substances within a normal range.

Common Health Problems of Preemies

Premature infants are prone to a number of problems, mostly because their internal organs aren't completely ready to function on their own. In general, the more premature the infant, the higher the risk of complications.
Hyperbilirubinemia

A common treatable condition of premature babies is hyperbilirubinemia, which affects 80% of premature infants. Infants with hyperbilirubinemia have high levels of bilirubin, a compound that results from the natural breakdown of blood. This high level of bilirubin causes them to develop jaundice, a yellow discoloration of the skin and whites of the eyes. Although mild jaundice is fairly common in full-term babies (about 60%), it's much more common in premature babies. Extremely high levels of bilirubin can cause brain damage, so premature infants are monitored for jaundice and treated quickly, before bilirubin reaches dangerous levels. Jaundiced infants are placed under special lights that help the body eliminate bilirubin. Rarely, blood exchange transfusions are used to treat severe jaundice.

Apnea

Apnea is another common health problem among premature babies. During an apnea spell, a baby stops breathing, the heart rate may decrease, and the skin may turn pale, purplish, or blue. Apnea is usually caused by immaturity in the area of the brain that controls the drive to breathe. Almost all babies born at 30 weeks or less will experience apnea. Apnea spells become less frequent with age.

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