USA (Commonwealth Union)_ Newborn screening tests are performed to detect developmental, metabolic, and hereditary abnormalities in infants. Early discovery and diagnosis provide immediate treatment, thereby preventing or minimizing any future problems. The screening of newborns is generally done 48 to 72 hours after birth. In the western world, neonatal screening is compulsory. However, in other parts of the world, there is an urgent need for awareness.
The purpose of newborn screening is to discover potentially dangerous disorders in infants as early as possible, typically before the child develops symptoms of the disease. These screenings expedite the therapy, thereby minimizing or eliminating the potential repercussions of the illness. The majority of these disorders, if left untreated, can result in severe symptoms and effects, including permanent damage to the neurological system, intellectual, developmental, and physical disorders that may even cause death.
Generally, newborn screening tests vary according to the country. However, the basic screening remains the same worldwide. The following are some of the primary newborn screening tests.
- Blood test – A few drops of blood from the baby’s heel are used to perform this test, which is subsequently submitted to a laboratory for examination.
- Hearing test – The doctor performs the hearing test by inserting a tiny earpiece or microphone into the infant’s ear. Another method involves placing electrodes on the infant’s head while it is sleeping.
- CCHD screen – This test employs an oximeter to assess the baby’s oxygen levels in the hand and foot. A small, soft sensor from the baby’s skin is attached to a machine called an oximeter, for a few minutes. The critical congenital heart disease (CCHD) is predicted to impact two out of every 1,000 newborns in the United States each year. Pulse oximetry is a noninvasive technique that monitors the amount of oxygen in the blood and can be used to detect infants who have CCHD prior to their exit from the newborn nursery.
- Galactosemia is a genetic condition, where the infant is incapable of metabolizing galactose, a milk sugar. It is predicted to affect around one infant in every 53 000 births. Without therapy (milk abstinence), galactosemia is potentially fatal. Symptoms may manifest within two weeks of birth. Most of the countries perform galactosemia screenings.
- Homocystinuria is a hereditary illness that causes intellectual disabilities, bone damage, and blood clots in one in 200,000 newborns. It is due to a lack of the enzyme required to digest the amino acid methionine.
- Congenital hypothyroidism is a disorder in which the infant is born with inadequate amounts of thyroid hormone. Approximately one in 2,500 to 3,000 US infants are born with hypothyroidism, a figure that has nearly risen over the previous two decades. Unaddressed hypothyroidism can result in mental development issues and stunted growth. Most of the countries do hypothyroidism screenings.
Other diagnostic procedures check for conditions such as cystic fibrosis, amino acid disorders, hemoglobin disorders, organic acid disorders, fatty acid oxidation disorders, lysosomal storage diseases, and severe combined immunodeficiency. Screening tests help determine whether infants require further testing to confirm or rule out diseases. Following the confirmation of a specific ailment after follow-up testing, the physician can begin therapy prior to the onset of symptoms.
Blood screening tests aid in the detection of diseases such as phenylketonuria (PKU), congenital hypothyroidism (thyroid gland is missing or undeveloped from birth), sickle cell illness, and maple syrup urine disease. These disorders can lead to brain damage, intellectual disability, behavioral issues, or convulsions if not addressed in time. Most tests cannot be conducted until a newborn has had breast milk or formula for at least 24 hours. If the mother is discharged before this period, or if the infant is unable to be tested before discharge, the child may require follow-up testing.
