Newborn screening is the practice of detecting harmful or life-threatening conditions that may affect the health or survival of the baby. This process can prevent death or health problems and protect the baby from some diseases and medical conditions. Newborn screening began in the 1960s when many US states established a newborn testing program for phenylketonuria (PKU) using the Guthrie method, a system for collecting and transporting blood samples on filter paper. Many children showed developments during treatment. This success led to the addition of tests for other metabolic diseases. Over time, tests for endocrine disorders were added, and the newborn screening program now includes more than 50 individual conditions. Newborn screening is a 5-part system in which the pediatrician plays a fundamental role. Part 1: Newborn testingBoth the obstetrician and the doctor The pediatrician has the responsibility to educate parents about the availability of newborn screening tests, the benefits of early diagnosis of disorders, the risks of not receiving screening, the screening process and follow-up and government requirements that may exist. The pediatrician should also be aware of factors that may influence the results of a specific screening test. Part 2: Follow-up Proper follow-up of an “abnormal” screening result is critical. The main function of the follow-up program is to identify newborns with abnormal screening results and facilitate timely diagnostic testing and management. Part 3: Diagnostic Testing Many of the disorders identified by newborn screening programs are heterogeneous. For adequate screening, specialized laboratory testing, interpretation and treatment... half of the document ...... which tests the genetic potential of the parents for producing additional children with cystic fibrosis and, through pre-symptomatic identification, allows the family to avoid months or years of delay in correctly diagnosing a child with chronic respiratory problems or poor growth.4. Endocrine disordersCongenital hypothyroidismCongenital hypothyroidism is the most common disorder identified by routine newborn screening. It is found in approximately 1:3,000 screened newborns (Dussault, 1993). The main clinical features of untreated congenital hypothyroidism are growth retardation and cognitive development delay leading to mental deficit. Congenital adrenal hyperplasia CAH caused by steroid 21-hydroxylase deficiency occurs in 1:16,000 to 1:20,000 births. Infants with the salt-wasting form of CAH can rapidly become hyperkalemic and die, often without a specific diagnosis.