– Collecting blood before 24 hours will result in false positive results. 

– After 72 hours, blood collection can still be performed without affecting the test result.

– However, sampling too late will not ensure early detection and timely treatment. Therefore, the ideal time to perform a screening test is between 48 and 72 hours after the baby’s birth for accurate results and early preventive measures.

Congenital hypothyroidism: The disease causes thyroid dysfunction and is characterized by signs of myxedema, jaundice, and growth retardation. If not diagnosed early and treated promptly, it will result in psychomotor retardation in children.

– G6PD deficiency: Deficiency of the enzyme will result in hemolytic anaemia and newborn jaundice due to fragile red blood cells. In infants, excess free bilirubin penetrates the brain, causing irreversible brain damage and affecting the child’s brain development in the future.
Congenital adrenal hyperplasia in two forms:

+ Salt-wasting form: hyponatremia, hyperkalemia, dehydration, low blood pressure, slow weight gain and hypoglycemia

+ Simple virilization: masculinization in females; clitoris enlargement; fusion of the labial folds. Early puberty in boys.

– Galactosemia: Infants who are intolerant to galactose in milk can lead to cataracts, psychomotor retardation, and even mortality if not treated promptly.

– Phenylketonuria: Causes a deficiency in the enzyme that facilitates phenylalanine metabolism (found in milk and protein foods). It will result in irreversible brain damage, a small head and intellectual disability if not treated promptly.