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IMPORTANCE OF NEWBORN SCREENING
The March of Dimes Birth Defects Foundation is committed to preventing birth defects and ensuring healthy outcomes of all pregnancies. One of the great advances in preventive medicine has been newborn screening for several diseases. Diagnosis and treatment of hypothyroidism and phenylketonuria (PKU) based on effective newborn screening stand as dramatic examples of this process. We applaud the current effort by the American Academy of Pediatrics1 to review what is being done throughout the country and what improvements can be made in the near future.
Although there is much in the report1 with which we agree, we must take issue with it in several respects. We would like to see in it as it is a document of the Academy an argument for the consumers, our children, rather than for an effort to achieve a cost-benefit balance. We believe that a test (even for a rare disease) as long its early discovery makes a difference to the childmust be conducted for every newborn. We believe that a currently available test should be abandoned for a newer one, if the latter achieves a greater precision and offers a shorter turnaround time, no matter what the cost differential. There should also be a requirement for timely reporting of positive test results. This need is made greater by the circumstance of early discharge
currently in vogue and potential loss to follow-up of children whose presentation of the problem may be missed. We believe that there is need for an overarching authority that would ensure uniform quality of these tests, whether they are carried out in medically sophisticated academic centers or in primary care rural hospitals.
In approaching this subject, we would like to divide those conditions for which tests are available into several categories. First, those for which intervention is available and in which any delay would adversely affect the infant, for example, PKU, galactosemia, and possibly salt-losing congenital adrenal hyperplasia. Second, those for which a test is available, and knowing that the infant is affected would provide for anticipatory care, such as sickle cell disease, cystic fibrosis, and hearing impairment. Last, those conditions for which tests are available, but whose current management cannot yet offer an advantage with early detection. As our knowledge expands, many shifts into the first category will take place, and new conditions for which now there is no available test will become subjects of newborn screening.
With respect to the question of the quality of the tests, we favor adoption of the best available tests and would call for a mandatory uniformity among the states in carrying these out. This is not an issue of cost-benefit ratio, but rather of sound medical practice, even though prevention of some of these potential problems is, in fact, highly beneficial economically.
The report would be more satisfactory if it examined systematically every available test, categorized these tests in terms of their quality, and then recommended steps toward assurance of quality control to provide national uniformity. An additional assessment of the tests on the basis of urgency, ie, those that make an immediate difference, those that make an important, but not crucial difference, and those that are only useful as part of basic information, should be also included.
DISORDERS
When tests for correctable conditions are universally available and their uniform quality is ensured, it may well turn out that the cost-benefits of this effort are highly favorable. Nevertheless, the primary consideration should be the health of the infant!
Do you know that there silent diseases which can occur rarely but are potentially fatal? We call them ‘silent diseases’ because they are not apparent at birth. Yet, as the baby grows up, his normal physical and mental development is delayed or stunted, leading to severe mental retardation, growth deficiency, immune system impairment, poor muscle control, blindness, and even death.
Many of these diseases are inherited metabolic disorders, wherein the baby lacks a specific enzyme or hormone needed for chemical process to occur within living cells of the body. Because the signs and symptoms of these disorders are not evident during the early years of the child’s development, diagnosis comes late usually only after mental retardation has already kicked in. But this was then.
Researchers have developed blood tests that screen newborns for these disorders. Such scientific effort was made after experts found out that early detection of every disease will actually offer babies some long-term benefits. This is known as the newborn screening.
Within 48 hours of the baby’s birth, the heel of the baby is pricked to obtain a small sample of blood which is then placed on a piece of filter paper, allowed to dry, and sent to a laboratory for testing. The result of this screening test will take weeks. The manner of reporting the result of the
test depends on the examining laboratory, but most of the time, the lab will call the physician in the case of abnormal results, while normal results will be sent through mail. If the test results come back abnormal, your baby will still undergo a confirmatory test through blood sample. Try not to panic because false positive results are possible, which most of the time, turn out to be normal after further testing.
When test results show that the baby has a birth defect, early diagnosis and treatment can make the difference between lifelong disabilities and healthy development. Take for instance the following conditions:
Congenital hypothyroidism. Most commonly identified by routine screening, affected babies don’t have enough thyroid hormone so that they develop slowing of growth and mental retardation. If detected early, the baby can be treated with hormone replacement and baby grows normally.
Phenylketonuria (PKU). Babies with this disorder can not process the amino acid phenylalanine which is present in almost all foods. This leads to the build up of phenylalanine in the blood, which causes brain damage. If detected early, the baby will be saved from mental retardation by simply putting the child on a low-phenylalanine diet by cutting out all high protein foods.
Galactosemia. Babies having this disorder can not convert galactose (sugar found in milk) into glucose in order to be used by the body. Galactose builds up causing blindness, mental retardation and even death during infancy. This can be prevented by just eliminating milk and other dairy products from the baby’s diet.
Sickle cell disease. This is an inherited blood disorder wherein the baby’s red blood cells assume abnormal shapes causing damage to vital organs, and placing the baby at risk for life-threatening bacterial infections. If detected early, doctors are alerted to begin antibiotic prophylaxis before infections set in.
Congenital adrenal hyperplasia. Babies with this disorder lacks hormones that can affect the development of external genitalia. Babies can also die due to loss of salts in the kidneys. If diagnosed early, babies can be treated through life-long supplementation of the missing hormones.
There are a lot more metabolic disorders that can be detected in newborn screening. However, it should be understood that there is no current federal standard as to which disorders newborns are tested. Screening varies widely from different states. It is best to ask your health care provider which tests are routinely done in your state.
According to the Center for Disease Control, at least 4 million babies in the US are tested each year, of which 5,000 severe diseases are detected in newborns. Today, thousands of children are living healthy and productive lives in spite of their underlying metabolic condition as a result of newborn screening.
