Infant screening

Institute of child health (newborn infants screening data for metabolic, genetic, and endocrine disorders)... 

TSH levels were analyzed for 1,081 of 11,200 infants screened in Alberta, Canada, during the period January 1, 1992 through March 31, 1992. Infants were selected sequentially until a minimum of 100 infants were selected for each of the first five days of life. The proportion of these infants by day of life screened was 119 (11.0%) for day 1 499 (46.2%) for day 2 252 (23.3%) for day 3 106 (9.8%) for day 4 and 105 (9.7%) for day 5. The birth weight and medical condition of the infants were not available. Premature infants were more likely to be screened on day 5 of life. No other screening practices related to day of life screened were reported. All specimens were processed at the University of Alberta Hospital, Edmonton, Canada. 

The acutely ill newborn and infant screening for the organic acidurias... 

The second method for mixture analysis is the use of specialized software together with spectral databases. We have developed a mixture analysis program AMIX for one- and multidimensional spectra. The most important present applications are the field of combinatorial chemistry and toxicity screening of medical preparations in the pharmaceutical industry. An important medical application is screening of newborn infants for inborn metabolic errors. 

In addition to blood, certain types of specimens are submitted to the Pediatric laboratory which would not be commonly seen elsewhere. An example of this is sweat for analysis of chloride. The process of obtaining the sweat by iontophoresis usually falls to the personnel of the Laboratory of Neonatology (17). Stool for analysis of lipids and trypsin is more commonly submitted to the Laboratory of Neonatology than to the laboratory which services the adult population. The reason for this is that one is screening for certain intestinal diseases characteristic of infants and newborns which are rare in adults. Such conditions would be celiac disease, cystic fibrosis and others. 

Urine toxicology screens from the mothers and infants were obtained during the labor and delivery and/or postnatal periods. 

For all 12 mother-infant pairs, either the mother or the infant s toxicology report was subsequently positive for PCP. In nine cases, the screens for both mother and infant were positive. In two cases, the mother s results were positive and the infant s were negative. In one case, the infant had a positive result while the mother s test was negative. Test sensitivity, specimen handling procedures, and delays in obtaining specimens undoubtedly contributed to the inconsistency in paired results. Cocaine, codeine, and glutethemide, in addition to phencyclidine, were identified in the urine toxicology screens of two mothers and their neonates. 

Congenital hypothyroidism is still seen in the United States, and all newborns in the United States undergo screening with a TSH level. As soon as the hypothyroid state is identified, the newborn should receive the full LT4 replacement dose. The replacement dose of LT4 in children is age-dependent. In newborns, the usual dose is 10 to 17 mcg/kg per day. LT4 tablets may be crushed and mixed with breast milk or formula. Serum FT4 levels (target 1.6-2.2 ng/dL or 20.59-28.31 pmol/L) are used for dose titration in infants because the TSH level may not respond to treatment as it does in older children and adults. By 6 months of age, the required dose is reduced to 5 to 7 mcg/kg per day, and from ages 1 to 10 years, the dose is 3 to 6 mcg/kg per day. After age 12, adult doses can be given. 

Most health care workers are at risk for exposure to many diseases in the normal course of their work. Additionally, health care workers may transmit vaccine-preventable diseases to their patients. At the time of employment and on a regular basis, health care workers should be screened for immunity to measles, rubella, and varicella if found to be non-immune, the measles, mumps, and rubella, and varicella vaccines should be administered. The hepatitis B series should be given if not already completed. Tetanus should be updated and given every 10 years. Health care personnel in hospitals and ambulatory settings with direct patient contact should receive Tdap if not already received an interval as short as 2 years from the last tetanus-containing vaccine should be used. Priority for receiving Tdap should be given to personnel with direct contact with infants less than 12 months of age. 

Today, mass spectrometers will soon be used to screen millions of infants worldwide in both modem and developing nations. It demonstrates the power and progress of MS technology in clinical applications. The method is described briefly here, with appropriate illustrations to support the concepts presented previously and demonstrate through one example how a mass spectrometer is used in medicine. 

Newborn screening is used just after birth to identify genetic disorders that can be treated early in life. Millions of babies are tested each year in the United States. All states currently test infants for phenylketonuria (a genetic disorder that causes mental retardation if left untreated) and congenital hypothyroidism (a disorder of the thyroid gland). Most states also test for other genetic disorders. 

Infants with classic phenylketonuria (PKU) are normal at birth but if untreated show slow development, severe mental retardation, autistic symptoms, and loss of motor control. Children may have pale skin and white-blonde hair. The neurotoxic effects relate to high levels of phenylalanine and not to the phenylketones from which the name of the disease derives. Infants are routinely screened a few days after birth for blood phenylalanine level. Treatment consists of a life-long semisynthetic diet restricted in phenylalanine (smalt quantities are necessary because it is an essential amino acid). Aspartame (N-aspartyl-phenylalanine methyl ester), which is widely used as an artificial sweetener, must be strictly avoided by phenyiketonurics. 

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