Screening newborn babies using laboratory blood tests is important for the early diagnosis and treatment of certain rare genetic and congenital disorders. This is usually done within a few days of birth when the disorders would otherwise not be clinically apparent at this early age.
The vast majority of screening tests will be normal and most babies screened will not have any of the conditions tested for but, for the small number that do, the benefits of screening are enormous. Early treatment can improve their health and prevent severe disability or even death.
For these tests, a few drops of blood from a heel prick are soaked into a special card (dried blood spots), which is then sent to a specialist screening laboratory for testing. For babies with abnormal results (screen positive) the family will be contacted by a health professional and invited to meet a special clinical team so that the screening result can be confirmed, and if follow-up tests are positive, appropriate management/ treatment can be started without delay.
It is important to understand that not all cases of the disorders screened for will be picked up – in a very few cases false negative screening test will occur. Positive screen results can also be false positive results, and further testing may show the newborn baby does not have the disease.