Premature Babies

An infant (known as a preemie) born before the 37th week of gestation. While some premature babies can survive without special help, many need extra medical care in a neonatal intensive care unit (NICU) for their first few weeks. An NICU is designed to limit stress on the infant and meet basic needs of warmth, nutrition, and protection to assure proper growth and development.

About 9 percent of American infants are born prematurely. Babies who weigh less than three pounds five ounces at birth are most likely to develop complications; any baby weighing less than five and a half pounds needs some special help. Age in premature babies is often defined in the number of weeks after the baby was conceived until the baby is 40 weeks old, which is the average age of a full-term baby.

Cause
There are many causes of preterm delivery; usually, the cause is not within the mother’s control. She could have a hormone imbalance, a physically abnormal uterus, or a chronic illness or infection. Preterm delivery also is more likely to occur if a woman is over age 35, under age 19, or carrying multiple babies. Sometimes the cause is simply unknown. Other times, the problem may have been triggered by the mother’s lifestyle choices during pregnancy:

• smoking
• abusing alcohol or drugs
• poor nutrition
• not gaining enough weight
• exposure to physical stress
• poor prenatal care

Symptoms
Because they are born before development has been completed, premature infants often have problems with feeding, breathing, maintaining body temperature, and fighting infections. In general, the smaller (and more premature) the baby, the more likely and more serious the problems. Because of modern technology, more than 90 percent of premature babies who weigh a little less than two pounds survive. Those who weigh a little more than one pound have a 40 percent to 50 percent chance of survival, although their chances of complications are greater. They are prone to a number of problems, primarily because their internal organs are not completely ready to function on their own.

Hyperbilirubinemia This common treatable condition is characterized by high levels of bilirubin, a compound formed from the natural breakdown of blood. The high level of bilirubin causes a yellow discoloration of the skin and whites of the eyes (jaundice) that at very high levels cause brain damage. Jaundiced infants are placed under lights that help the body eliminate bilirubin. Rarely, blood transfusions are used to treat severe jaundice.

Apnea A condition in which a baby stops breathing, heart rate may drop, and skin may turn pale, purplish, or blue. Apnea is usually caused by an immature area of the brain that controls breathing. Almost all babies born at 30 weeks or less will experience apnea, which becomes less frequent with age (by 50 postconceptional weeks, apnea is rare). All premature babies are monitored for apnea; if it occurs, the baby is gently stimulated to restart breathing. If apnea occurs frequently, the infant may require medication (most commonly caffeine or theophylline) and a special nasal device that blows a steady stream of air into the airways to keep them open.

Anemia Many premature babies do not have enough red blood cells to carry sufficient oxygen throughout the body. This is easily diagnosed in the lab, which can determine the severity of anemia and the number of new red blood cells being produced. Some premature infants require red blood cell transfusions.

Low blood pressure This is a relatively common complication that may occur shortly after birth due to infection, blood loss, fluid loss, or medications given to the mother before delivery. Low blood pressure is treated by boosting fluid intake or giving medication.

Respiratory distress syndrome (RDS) Breathing problems are one of the most common and serious problems of prematurity. With respiratory distress syndrome (RDS), (formerly known as hyaline membrane disease), the infant’s immature lungs do not produce enough surfactant, which normally allows the inner surface of the lungs to expand properly when the infant makes the change from the womb to breathing air after birth. RDS is treatable and many infants do quite well.

If premature delivery cannot be stopped, most pregnant women are given medication just before delivery to help prevent RDS. Immediately after birth and several times later, artificial surfactant can be given to the infant. Although most premature babies without enough surfactant will need a ventilator, the use of artificial surfactant has greatly decreased the amount of time one is necessary.

Bronchopulmonary dysplasia (BPD) A lung reaction to oxygen or a ventilator used to treat a lung infection, severe RDS, or extreme prematurity. Preemies are often treated with medication and oxygen for this condition.

Infection This is a threat to premature infants, who are less able than full-term infants to fight germs that can cause serious illness. Infections can be passed on from the mother or be acquired after birth.

Patent ductus arteriosus The ductus arteriosus is a short blood vessel that connects the aorta (main blood vessel leaving the heart) to the main blood vessel supplying the lungs. In an unborn baby, it allows blood to bypass the lungs, since oxygen comes from the mother and not from breathing air. In full-term babies, the ductus arteriosus closes shortly after birth, but it often stays open in premature babies. When this happens, too much blood flows into the lungs and can cause breathing problems and sometimes heart failure. This condition is often treated with a medication called indomethacin, which can successfully close the blood vessel in more than 80 percent of cases. If indomethacin fails, surgery may be required to close the vessel. Maintaining an open ductus is a requirement for the successful treatment of some congenital heart diseases.

Retinopathy of prematurity Abnormal growth of the blood vessels in an infant’s eye. About 7 percent of very small premature babies develop retinopathy of prematurity (ROP), and the resulting damage may range from needing glasses to blindness. Experts do not know what causes ROP, but oxygen levels (either too low or too high) are only a contributing factor. Premature babies receive eye exams in the NICU to check for this condition.

Treatment
Premature babies need a great deal of special care to survive. Because they lack the body fat necessary to maintain their body temperature, even when swaddled with blankets, incubators or radiant warmers are used to keep these babies warm. Premature babies also have special nutritional needs because they grow at a faster rate than full-term babies and their digestive systems are immature.

Although breast milk is an excellent source of nutrition, preemies are too immature to feed directly from the breast or bottle until they are 32 to 34 postconceptional weeks old. Most premature infants have to be fed slowly because of the risk of developing an intestinal infection. Breast milk can be pumped by the mother and fed to the premature baby through a gastric tube directly into the stomach. The baby’s blood chemicals and minerals are monitored regularly, and the baby’s diet is adjusted to keep these substances within a normal range.

Because some studies have suggested that the bright, noisy environment of the NICU was not the best place for seriously ill tiny babies. Many NICUs now try to use soft lighting, a quiet environment, and provide as little disruption as possible. Health care experts and parents try to handle premature babies as slowly and carefully as possible, because they are sensitive to abrupt motions. Handling is important to their development, however, and parents are encouraged to provide skin-to-skin contact in the course of routine care.

After the NICU
After leaving the NICU, infants who were born too soon occasionally still need attention at a high-risk newborn clinic or early intervention program. In addition to the regular well-child visits and immunizations that all infants receive, premature infants also get periodic hearing and eye examinations. Careful attention is paid to the development of the nervous system, including the achievement of motor skills like smiling, sitting, and walking, as well as the positioning and tone of the muscles. Speech and behavioral development are also important in these babies; some premature infants may require speech therapy or physical therapy as they grow up. Infants who have experienced complications in the NICU may need additional care by medical specialists.

For the first few years most children who were born too soon are still small for their age, although their growth rate is usually normal. Although a few born prematurely may have permanent problems such as CEREBRAL PALSY, most have no serious longterm effects.