What is neonatology? |

Science and Profession

Neonatology has grown dramatically since its beginnings in the late 1960s, and neonatologists have become an integral part of the obstetric-pediatric team at major medical centers throughout the world. In addition to being cared for by physicians who specialize in neonatology, some neonatal infants, in particular those who are critically ill or premature, are cared for by nurse practitioners with the specialty certification of neonatal nurse practitioner (NNP). In large part because of an ever-expanding technological base and marked advances in scientific research, these health-care professionals have changed the outlook for premature and sick newborns.

As a subspecialty of pediatrics, neonatology is concerned with the most critical time of transition and adjustment—the first four weeks of life, known as the neonatal period—whether the infant is healthy (a normal birth) or sick (as a result of genetic problems, obstetric complications, or medical illness). By the early 1970s, it had become increasingly clear to health administrators that hospitals throughout the United States had varying abilities to care for medical and pediatric cases requiring the most sophisticated staff and equipment. Consequently, they developed a system that designated hospitals as either level I (small, community hospitals), level II (larger hospitals), or level III (major regional medical centers, also called tertiary care centers). It was in the last group that the most advanced neonatal care could be given. In these major centers, there are two types of nurseries: the routine nursery, for normal, healthy infants, and the neonatal intensive care unit (NICU), for sick or high-risk infants.

Routine nurseries are the temporary home of the vast majority of newborns. The services of the neonatologist are rarely needed here, and the general pediatrician or family practitioner observes and examines the infant for twenty-four to forty-eight hours to be sure that it has made a smooth transition from intrauterine to extrauterine life. These babies soon leave the hospital for their homes. Those neonates with minor problems arising from multiple births, difficult deliveries, mild prematurity, or minor illnesses are easily managed by a primary care physician in consultation with a neonatologist, perhaps at another hospital.

It is in the NICU that the most difficult situations present themselves. Here, several teams of pediatric subspecialists—surgeons, cardiologists, anesthesiologists, and highly trained nurses, along with many other health professionals—are led by a neonatologist, who coordinates the team’s efforts. These newborns have life-threatening conditions, often as a result of extreme prematurity (more than six weeks earlier than the expected date of delivery), major birth defects (genetic or developmental), severe illnesses (such as overwhelming infections), or being born to drug- or alcohol-addicted mothers. They require the most advanced technological and medical interventions, often to sustain life artificially until the underlying problem is corrected. It is in this setting that the most dramatic successes of neonatology are found.

After hours of being inside a forcefully contracting uterus and sustaining the stress of passing through a narrow birth canal, the newborn emerges into a dry, cold, and hostile environment. The umbilical cord, which has provided oxygen and nutrients, is clamped and cut; the fluid-filled lungs must now exchange air instead, and the respiratory center of the infant’s brain begins a lifetime of spontaneous breathing, usually heralded by crying. The vast majority of neonates make this extraordinary adjustment to extrauterine life without difficulty. The newborn is evaluated, first at one minute and again at five minutes after birth, and scored on five physical signs: heart rate, breathing, muscle tone, reflexes, and skin tone. These Apgar scores, named for neonatology pioneer Virginia Apgar, evaluate the need for immediate resuscitation. A brief physical examination follows, which can identify other life-threatening abnormalities.

It is essential to remember that the medical history of a neonate is in fact the medical and obstetric history of its mother, and seemingly normal infants may develop problems shortly after birth. Risk factors include very young or middle-aged mothers; difficult deliveries; babies with Rh-negative blood types; mothers with diabetes mellitus, kidney disease, or heart disease; and concurrent infections in either the mother or the baby. Anticipating these problems of the healthy newborn by using the Apgar scores and the results of the physical examination allows the proper assignment of the infant to the nursery or NICU.

The NICU is a daunting place containing high-tech equipment, a tangle of wires and tubes, the sounds of beeps and alarms, and tiny, fragile infants. All this technology serves two simple purposes: to monitor vital functions and to sustain malfunctioning or nonfunctioning organ systems. Looked at individually, however, the machines and attachments become much more understandable. The incubator, perhaps the most common device, maintains a warm, moist environment of constant temperature at 37 degrees Celsius (98.6 degrees Fahrenheit). Small portholes with rubber gloves allow people to touch the child safely. Generally, the infants will have small electrodes taped on their chests, connected to video monitors that record the heart and breathing rates and that will sound alarms if significant deviations occur. These monitors will also record blood pressure through an arm or thigh cuff. To ensure immediate access to the blood, for delivering medications and taking blood for testing, catheters (plastic tubes) are placed into larger arteries or veins near the umbilicus, neck, or thigh (in adults, intravenous access is found in the arms).

The remaining equipment is used for the very serious business of life support, in particular the support of the respiratory system. Maintaining adequate oxygenation is critical and can be accomplished in several ways, depending on the baby’s needs. The least stressful are tubes placed in the nostrils or a face mask, but these methods require that breathing be spontaneous although inadequate. More often, unfortunately, neonates with the types of problems that bring them to an intensive care unit cannot breathe on their own. In these cases, a tube must be connected from the artificial respirator into the windpipe (the endotracheal tube). Warm, moistened, oxygen-rich air is delivered under pressure and removed from the lungs rhythmically to simulate breathing. Tranquilizers and paralytic agents are used to calm and immobilize the infant. Sick or premature infants are also generally unable to feed or nurse naturally, by mouth. Again, several methods of feeding can be employed, depending on the problems and the length of time that such feedings will be needed. For the first few days, simple solutions of water, sugar, and protein can be given through the intravenous catheters. These lines, because of the very small, fragile blood vessels of the newborn, are seldom able to carry more complex solutions. A second method, known as gavage feeding, employs tubing that is inserted through the nose directly into the stomach. Through that tube, infant formula (water, sugar, protein, fat, vitamins, and minerals) and, if available, breast milk can be given.

As the underlying problems are resolved, the infant is slowly weaned, first feeding orally and then breathing naturally. Next, the infant will be placed in an open crib, and gradually the tangled web of tubes and wires will clear. With approval from the neonatologist, the baby is transferred to the routine nursery, a transitional home until discharge from the hospital is advisable.

Diagnostic and Treatment Techniques

Neonatology has amassed an enormous body of knowledge about normal neonatal anatomy and physiology, disease processes, and, most importantly, how to manage the wide variety of complications that can occur. Specific treatment protocols have been developed and are practiced uniformly in all NICUs. Short-term stays (twenty-four to forty-eight hours) are meant to observe and monitor infants with respiratory distress at birth that required immediate intervention. Long-term stays, lasting from several weeks to months, are the case for the sickest newborns, most commonly those with severe prematurity and low birth weight (less than 1,500 grams), respiratory distress syndrome (also known as hyaline membrane disease), congenital defects, and drug or alcohol addictions.

Infants born prematurely make up the majority of infants at high risk for disability and death, and each passing decade has seen younger and younger babies being kept alive. While many maternal factors can lead to preterm delivery, often no explanation can be found. The main problem of prematurity lies in the functional and structural immaturity of vital organs. Weak sucking, swallowing, and coughing reflexes lead to an inability to feed and a danger of choking. Lungs that lack surfactant, a substance that coats the millions of tiny air sacs (alveoli) in each lung to keep them from collapsing and sticking together after air is exhaled, cause severe breathing difficulty as the infant struggles to reinflate the lungs. When premature delivery is inevitable but not immediate, lung maturity can be increased by administration of steroids to the mother. An immature immune system cannot protect the newborn from the many viruses, bacteria, and other microorganisms that exist. Inadequate metabolism causes low body temperature and inadequate use of food or medications. Neurological immaturity can lead to intellectual or developmental disabilities, blindness, and deafness.

Aggressive management of the preterm baby begins in the delivery room, with close cooperation between the obstetrician and the neonatologist. Severely preterm infants, some born after only twenty weeks of pregnancy, require immediate respiratory and cardiac support. Placement of the endotracheal tube, assisted ventilation with a handheld bag, and delicate chest compressions similar to the cardiopulmonary resuscitation (CPR) performed on adults to stimulate the heartbeat are each accomplished quickly. Once the respiratory and circulatory systems have been stabilized, excess fluid will be suctioned, while a brief physical examination is performed to note any abnormalities that require immediate attention. As soon as transport is considered safe, the newborn is sent to the NICU. If the infant has been delivered at a small community hospital, this may involve ambulance or even helicopter transport to the nearest tertiary care center.

Once in the unit, the neonate will be placed in an incubator and attached to video monitors that record heart rate, breathing, and blood pressure. The endotracheal tube can now be attached to the respirator machine, and intravenous or intra-arterial catheters will be placed to allow the fluid and medication infusions and the blood drawing for the battery of tests that the neonatologist requires. Feeding methods can be set up as soon as the infant has stabilized. Within a short time after delivery, the premature newborn has had a flurry of activity about it and is surrounded by the most sophisticated equipment and staff available. Supporting the immature organs becomes the first priority, although the ethical issues of saving very sick infants must soon be addressed as complications begin to occur. Nearly 15 percent of surviving preterm infants with a birth weight of less than two thousand grams have serious physical and mental disabilities after discharge. The majority, however, grow to lead normal, healthy lives.

Congenital defects are common, and it is estimated that the majority of miscarriages are a direct result of congenital defects that are incompatible with life. Many infants that do survive development and delivery die shortly after birth despite the most sophisticated and heroic attempts to intervene. The causes of such defects are arbitrarily assigned to two broad categories, although a combination of these factors is the most likely explanation: genetic errors (such as breaks, doubling, and mutations) and environmental insults (such as chemicals, drugs, viruses, radiation, and malnutrition). In the United States, the most common birth defects that require immediate intervention include heart problems, spina bifida (an open spine), and tracheoesophageal fistulas and esophageal atresias (wrongly connected or incomplete wind and food pipes).

The birth of a malformed infant is rarely expected, and the neonatologist’s team plays a key role in its survival. Congenital heart disease is the most prevalent life-threatening defect. During development in utero, the umbilical cord supplies the necessary oxygen; it is not until birth, when that lifeline is cut, that the neonate’s circulatory and respiratory systems acquire full responsibility. At delivery, all may appear normal, and the one-minute Apgar score may be high. Several minutes later, however, the pink skin color may begin to darken to a purplish blue (cyanosis), indicating that insufficient oxygen is being extracted from the air. Immediately, the infant receives rescue breathing from the bag mask. Upon admission to the neonatal unit, the source of the cyanosis must be determined. A chest x-ray may provide significant information about the anatomy of the heart and lungs, but special tests are usually needed to pinpoint the problem. Catheters that are threaded from neck or leg vessels into the heart can reveal the pressure and oxygen content of each chamber in the heart and across its four valves. Echocardiograms, video pictures similar to sonograms generated by sound waves passing through the chest, enhance the data provided by the x-rays and catheterizations, and a diagnosis is made. Based on the physical signs and symptoms of the newborn, a treatment plan is devised.

Because of the nature of congenital defects and structural abnormalities, their correction generally requires surgery. Openings between the heart’s chambers (septal defects), valves that are too narrow or do not close properly, and blood vessels that leave or enter the heart incorrectly are all common defects treated by the pediatric heart surgeon. Because of the delicacy of the operation and the vulnerability of the newborn, surgery may be postponed until the baby is larger and stronger while it is provided with supplemental oxygen and nutrients. The risk of such operations is high, and depending on the degree of abnormality, several operations may be required.

Another group of infants who have benefited from advances in neonatology are those born to drug-addicted women. The lives of these infants are often complicated by congenital defects and life-threatening withdrawal symptoms. For example, heroin-addicted babies are quite small, are extremely irritable and hyperactive, and develop tremors, vomiting, diarrhea, and seizures. The newborn must be carefully monitored in the unit, and sedatives and antiseizure medications are given, sometimes for as long as six weeks. Cocaine and its derivatives frequently cause premature labor, fetal death, and maternal hemorrhaging during delivery. Infants that do survive often have serious congenital defects and suffer withdrawal symptoms. The risk of acquired immunodeficiency syndrome (AIDS) adds another dimension to an already complicated picture.

Perspective and Prospects

Throughout human history, maternal and neonatal deaths have been staggering in number. Ignorance and unsanitary conditions frequently resulted in uterine hemorrhaging and overwhelming infection, killing both mother and baby. Highly inaccurate records from the beginning of the twentieth century in New York City show maternal death rates averaging 2 percent; in fact, the rate was probably greater, since most births occurred at home. Neonatal deaths from respiratory failure, congenital defects, prematurity, and infection loom large in these medical records. The expansion of medical, obstetric, and pediatric knowledge and technology that began after World War II has dramatically lowered maternal and infant mortality. It should not be forgotten, however, that nonindustrialized nations, the majority in the world, remain devastated by the neonatal problems that have plagued civilization for thousands of years.

Ironically, the problems associated with neonatology in Western nations are now at the other end of the spectrum: saving and prolonging life beyond what is natural or “reasonable.” As neonatology advanced scientifically and technically, saving life took precedence over ethical issues. The famous and poignant story of Baby Doe in the early 1980s illustrates the dilemmas that occur daily in neonatal intensive care units. Baby Doe was a six-pound, full-term male born with Down syndrome and severe congenital defects of the heart, trachea, and esophagus. These malformations were deemed surgically correctable, although the underlying problem of Down syndrome, a disease characterized by intellectual disabilities and particular facial and body features, would remain. The parents did not agree to any operations and requested that all treatment be withheld. Baby Doe was given only medication for sedation and died within a few days. The case was later related by the attending physician in a letter to the New England Journal of Medicine, sparking enormous controversy. On July 5, 1983, a law was passed in effect stating that all newborns with disabilities, no matter how seriously afflicted, should receive all possible life-sustaining treatment unless it is unequivocally clear that imminent death is inevitable or that the risks of treatment cannot be justified by its benefit. The legislators believed that Baby Doe had been allowed to die because of his underlying condition of Down syndrome.

Since then, attorneys, ethicists, juries, and courts have used the example of Baby Doe, and the law that grew from it, to interpret many cases that have come to light. Life-and-death decisions are made on a daily basis in the neonatal care unit. They are always difficult, but they usually remain a private matter between the parents and the neonatologist. These cases become public matters, however, when the family disagrees with the medical staff. Then the question of what is in the best interest of the child is compounded by who will pay for the treatments and who will care for the baby after it is discharged.

Such ethical dilemmas will continue as expertise and technology grow. A multitude of questions, previously relegated to philosophy and religion, will arise, and the benefits of saving a life will have to be weighed against its quality and the resources necessary to maintain it.

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