Journal Issue: Low Birth Weight Volume 5 Number 1 Spring 1995
Medical Care for Low Birth Weight Infants
Horbar and Lucey document in their article tremendous advances in the development and utilization of neonatal intensive care treatments and drugs which have improved the survival of the tiniest babies in the past two decades. This same period has also witnessed improvements in the availability and accessibility of neonatal intensive care, and the advent of neonatal and perinatal subspecialists who are trained to care for the very tiny infant. Together, these advances have provided the capability to rescue a good proportion of the smallest infants.
The development, refinement, and availability of neonatal intensive care have been credited with saving the lives of many infants. While it is not known exactly how many babies have been saved by these means, marked declines in infant death rates have coincided with the introduction of neonatal intensive care and with its refinements. Horbar and Lucey note that three lines of evidence support the notion that neonatal intensive care saves lives. First, low birth weight infants born in hospitals having the highest level of neonatal intensive care are much more likely to survive than are infants born in hospitals having lower levels of care. Second, the development of a system of regionalized care for the very smallest infants who need the highest level care has allowed nearly all infants in the country access to neonatal intensive care. Finally, the decline in infant deaths in the past five years is attributed to the introduction of surfactant therapy, which makes it easier for very small infants to breathe outside the womb and reduces their susceptibility to serious lung disease.
McCormick and Richardson discuss how regionalized care was designed to provide expensive, high-level care for very sick infants in an effective and efficient manner. In a regionalized system, one neonatal intensive care unit is responsible for all of the infants from a large geographical area who require intensive care. This large population base helps to guarantee an adequate volume of patients and to assure both efficiency and quality of care. Regionalization also improved access to care by providing a centralized place for the care of all neonates within a region. No definitive studies have been conducted which document whether or not regionalization of neonatal intensive care was effective. However, there is indirect evidence which shows a sharp decrease in infant deaths after the introduction of regionalized care.
Recent trends toward deregionalization of neonatal intensive care services have resulted in the rapid proliferation of community-based care units. This increase in the number of neonatal intensive care units, particularly in suburban areas, has been stimulated in part by the fundamental changes in the way health care is organized and financed in the United States. The growth of large managed care health insurance providers has fueled the ongoing competition among providers and hospitals to attract insured families. It appears that some neonatal intensive care units are being established to attract young, insured families by assuring them that high-level infant care is available in their communities. An increase in the number of intensive care facilities in local communities may increase access to care, particularly for insured families. But large-scale deregionalization also has the potential to dismantle the current system of regionalized care. How these changes will affect the availability and distribution of neonatal intensive care is unknown.
The Limit of Survival
As the limit of survival is moved to smaller and smaller infants, many questions are raised about how neonatal intensive care technologies should be used. Currently, most infants born at 24 or more weeks of gestational age survive. One study reported that before 24 weeks, very few infants survive; at 23 weeks, only 15% of infants survive; and at 22 weeks, almost no infants survive.3 Tyson discusses in his article the difficult ethical questions health care providers, families, and society face when they must decide if an infant is so sick that neonatal intensive care should be stopped or not administered. While these ethical questions are certainly not new, recent advances in medical technology, which are often achieved at high cost, have brought these difficult questions to the forefront. More needs to be known about the decisions to initiate care, to identify when an infant is not responsive to care, and to withdraw care when necessary.
Tyson notes that current federal child abuse regulations mandate care for all live-born infants unless the infant is irreversibly comatose or is in a condition where treatment would be "futile" and merely prolong dying or would be "virtually futile" and inhumane. The withholding of medically indicated care is defined as child abuse and neglect. Unfortunately, the precise definitions of futile or inhumane are not provided, and the law gives no practical guidance for clinicians and families who must make these difficult decisions. Tyson argues that this law is much too simplistic and that a number of factors must be considered in deciding how to care for the very smallest infants. These factors include the probability of survival, pain and suffering, future quality of life, and the economic cost of care.
Long-Term Outcomes for Low Birth Weight Infants
Hack, Klein, and Taylor note that, while a large majority of low birth weight infants are normal and healthy, as a group they have higher rates of subnormal growth, adverse health conditions, and developmental problems. The number and severity of these problems increases as birth weight decreases. With the improved survival of more infants who were born too soon or too small comes increased numbers of children born with severe brain damage. The occurrence of cerebral palsy and other forms of brain injury is highly correlated with birth weight. Rates of brain injury total approximately 7% for moderately low birth weight infants (infants weighing between 1,500 and 2,500 grams [3 pounds, 5 ounces and 5 pounds, 8 ounces]) and increases to 20% among the smallest infants (infants weighing between 500 and 1,500 grams [1 pound, 2 ounces and 3 pounds, 5 ounces]). Hack, Klein, and Taylor also note that being born low birth weight is considered an index of biological risk because infants born low birth weight are more likely to have brain damage and/or lung and liver disease.
At school age, children who were born low birth weight are more likely than children of normal birth weight to have mild learning disabilities, attention disorders, developmental impairments, and breathing problems such as asthma.4 Children born very low birth weight have more learning problems and lower levels of achievement in reading, spelling, and math than moderately low birth weight children. These problems are reflected in much higher proportions of low birth weight children than normal birth weight children who are enrolled in special education programs (see the article by Hack, Klein, and Taylor). Approximately one-half of all very low birth weight children enroll in special education programs. The adverse consequences of being born low birth weight are still apparent in adolescence, and experts believe that these abnormalities will be lifelong and will not improve as the children enter adulthood. It must be emphasized that not all of these adverse consequences can be attributed solely to being born low birth weight. Some of the less severe but more common developmental and physical delays reflect the fact that low birth weight children are disproportionately more likely to come from disadvantaged environments. However, it has not been possible to separate the developmental and physical effects of a disadvantaged environment from the effects of being born low birth weight.
Some of the devastating effects of being born low birth weight can be reversed. Hack, Klein, and Taylor discuss how intensive enrichment programs which provide medical and educational services and support for both the parents and the child have been shown to improve short-term developmental outcomes for low birth weight children. Federal laws mandate that services for school-age disabled children (which include medical, educational, psychological, occupational and physical therapy, and other care) be expanded to include family-based care for infants. At present, these services are targeted to children born with severe congenital disabilities. The availability of services for moderately low birth weight children who do not have severe physical or biological problems varies from state to state, but for the most part, these services are not widely available.
It is not clear what the future holds for tiny infants who only five years ago would not have survived. Initial indications are that a fraction of these very small infants may not fare well and will require substantial commitments from their families, the medical care system, the educational system, and society in general.
While medical care and technology have gone a long way toward improving the survival of low birth weight infants, preventing the occurrence of low birth weight or preterm birth would be much more advantageous. The next section takes a realistic look at how and if low birth weight can be prevented.