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STATEMENT OF DUANE F. ALEXANDER
The United States is a nation that holds its children in high esteem. A child who dies prematurely or who fails to develop to its full human potential represents a societal as well as a personal tragedy.
The research programs of the National Institute of Child Health and Human Development (NICHD) are designed to ensure the health and well-being of American children and their families. That goal is pursued through the support and conduct of research addressing some of the urgent public health problems facing our nation. These problems include a high national infant mortality rate; maternal, pediatric and adolescent AIDS; unintended pregnancy, a large portion of which is teenage childbearing; Sudden Infant Death Syndrome; factors that inhibit the physical or behavioral development of children; and the physical disabilities that result from impaired development, accidents or disease.
The NICHD supports a broad range of biomedical and behavioral research on such challenges as birth defects, mental retardation or other developmental disabilities, learning disabilities, medical rehabilitation and the development of better, more effective fertility regulation, including contraceptive choices.
Improving the health status of mothers and infants remains a national challenge. In 1989, more than 4,000,000 babies were born in the United States. Of these, almost 39,000 died before their first birthday, with black babies dying at twice the rate of white babies.
Although the nation's infant mortality rate is at an all-time low, the pace of progress has slowed. Important determinants of infant mortality such as the incidence of low birth weight and early prenatal care show no recent improvements.
NICHD scientists are trying to determine why the nation's rate of low birth weight has remained constant and why low birth weight is twice as prevalent among black women as compared to white women. alone do not explain the disparity, and researchers are currently investigating the effect of social support, level of work and other physical activity, nutrition, stress, health behaviors and other factors on the occurrence of low birth weight among various ethnic groups including blacks
Sudden Infant Death Syndrome (SIDS), which claims the lives of 6,000 to 7,000 infants each year, continues to resist revealing its causes.
research is making some inroads.
Differences in the number of short pauses in breathing during sleep may be a clue as to why apparently healthy infants die. During the second month of life, babies who die of SIDS appear to have a decrease in the number of normal pauses in breathing. This decrease occurs just prior to the age at which most SIDS deaths occur, leading investigators to conclude that this change may be related to factors in the infant's respiratory control system. A prospective study being developed by NICHD will use the new technology of event recorders with apnea monitors to determine whether this decrease in breathing pauses or other factors may be able to predict, detect, or prevent apnea and SIDS.
The improvement in infant mortality that has been noted is largely attributable to advances in the technology of caring for ill or premature Assuring that these advances are transferred from the laboratory bench to the health care system is an Institute priority. Evidence of this commitment is the NICHD's' recent establishment of a national program of Child Health Research Centers. Seven Centers were funded last year in response to Congressional interest. This program is designed to foster the development of improved treatment techniques, expedite the transfer of these findings from basic research to the care of sick children, and encourage the development of a new generation of highly trained research clinicians specializing in pediatric research.
Survival of premature or low birth weight infants is not the only issue. The future intellectual and behavioral functioning of these children is also at stake. Low birth weight or premature infants often suffer developmental disabilities ranging from mild learning problems to severe mental retardation. The results from a large-scale study jointly supported by the Robert Wood Johnson Foundation and the NICHD demonstrated that early intervention can prevent many behavioral problems and raise I.Q. scores in at-risk children. The low birth weight children in the study began receiving weekly visits soon after birth from health care professionals who taught parents not only how to take care of their children's physical needs but also how to play with their children in ways that would stimulate their minds. At one year of age, the
children were enrolled in special child development centers. I.Q. scores at age 3 were significantly improved for infants of all birth weights who received the services. In contrast, nearly half of the at-risk children who did not receive the intervention program had I.Q. scores below 85, a level associated with significant learning problems. The Institute hopes to reassess these children at age 6 to ascertain if they have maintained the gains achieved.
It is intriguing to note that this research reinforces observations made in the laboratory that fetal mouse nerve cells respond to stimulation by increasing their connections to other cells. Using a unique apparatus, NICHD intramural scientists are able to study the effects of electrical impulses on sensory neurons. One group of neurons are stimulated while another group are not. The stimulated neurons respond with an overall increase in the efficiency with which nerve impulses are conducted. By contrast, the efficiency of the unstimulated neurons decreases. This research enhances our understanding of the formation of orderly connections between nerve cells
during normal development.
Scientists believe that disturbances in these
connections may be related to mental retardation or some forms of mental
Studies such as this demonstrate the vulnerability of the brain to disruption of its biochemical and electrical interactions.
Tangible evidence of this is provided by the damaged babies being born to cocaine-dependent mothers. It is estimated that as many as 375,000 infants may be affected by in-utero exposure to illicit drugs in the U.S. each year. In Fiscal Year 1991, the NICHD will start two projects related to this problem. Institute is conducting a comprehensive review of current information about the adverse effects of prenatal illicit drug use on fetal health, including possible long term effects, and, through its network of neonatal intensive care units, is leading a study involving several agencies to assess the impact of prenatal drug use on the development of the fetus's central nervous system. Infants in this study will be followed from birth until they enter school to monitor their progress.
In another longitudinal study involving children, NICHD-supported scientists at 10 centers around the country are assessing the effects of day
care on social, emotional, and intellectual development. Since approximately three-fourths of U.S. children under the age of two whose mothers are employed are cared for by someone other than a parent, it is important to ascertain the long-term effects of different types of day-care situations on children and their families. At least 1,200 children will be monitored at regular intervals from the time they are one month old through age three.
Science is in the very earliest moments of being able to apply what has been learned about genes and their control to the amelioration or prevention of disease or disability. Researchers supported by the NICHD recently
developed a mouse model for sickle cell anemia, an incurable genetic disorder afflicting about 50,000 black Americans. The availability of an animal model should prove valuable for testing new drugs and gene therapies to treat the disease.
To facilitate access to this new technology, the NICHD has established a National Transgenic Development Facility for the generation of "custom made" mice. This facility will make the technology of gene transfer more accessible to the basic research community at an affordable price. It is anticipated that as many as 100 animal models a year will be developed at this facility, accelerating research on many genetic disorders.
Just as basic research is beginning to yield results in gene therapy, it is paying off in other areas as well. Recently, the Food and Drug Administration licensed the first vaccine effective in infants against Haemophilus influenzae type b. This vaccine is based upon the work of NICHD intramural scientists. This vaccine, once it is widely used, should nearly eliminate H. flu meningitis as a cause of mental retardation and deafness.
Other vaccines are being developed against pertussis; salmonella; streptococcus Group B, associated with sepsis in the newborn; Shigella dysenteriae, the cause of epidemic diarrhea; and Staphylococcus aureus, often the source of life-threatening infection in burn patients and premature babies.
The number of women and children with HIV infection is increasing. Approximately 6,000 HIV-infected women gave birth last year, and about one out of three of these babies will be infected. NICHD-supported investigators have
found that monthly administration of intravenous immunoglobulin, a solution
that contains concentrated antibodies, significantly reduces the number of serious bacterial infections, reduces the number of hospitalizations required, and prolongs by as much as a year the time free from serious bacterial infections in children who are afflicted with symptoms of HIV infection. The results of this clinical trial were so compelling, it was terminated a year early so that the benefit of its findings could be made available immediately to all symptomatic HIV infected children.
In a joint effort with the National Institute of Allergy and Infectious Diseases, we are enrolling children with AIDS in other clinical trials, and beginning clinical trials in pregnancy to attempt to reduce transmission of the virus from mother to fetus.
Women's health has been a long-standing priority area of the NICHD, but the recent increase of HIV infection among women; the small but troubling upturn in the number of births to unmarried women, primarily teenagers; and the number of women encountering difficulties in achieving pregnancy have provided impetus for increased emphasis in this area. The NICHD intramural research program plans to expand significantly its research in gynecology to investigate hormonal, immunologic, genetic, and anatomic processes which lead to illness or infertility. In addition, the NICHD plans to fund several new centers over the next year. At least one center will focus on infertility research and as many as three will concentrate on contraceptive development.
Millions of Americans are encumbered by physical disability resulting from injuries or diseases. Helping these individuals regain their physical or functional ability to the fullest extent possible is consistent with the Institute's interest in human development and the maximization of potential. To help achieve this objective, a National Center for Medical Rehabilitation Research has been established within the NICHD. The new Center will conduct and coordinate research and research training related to the rehabilitation of individuals with physical disabilities resulting from problems such as arthritis, head or spinal cord injury, stroke, burns, birth defects, cerebral palsy, or genetic disorders.
This first year of a new decade has set the tone for the years ahead--the Institute has seen the maturation and fruition of research efforts of past years result in the availability of new products such as vaccines; the