Neonatal screening programmes

Many countries have screening programmes for diseases at birth. In the UK, newborns are screened for congenital hypothyroidism, phenylketonuria, cystic fibrosis, sickle-cell disease and medium-chain acyl CoA dehydrogenase deficiency. A blood sample is collected from every baby around the seventh day of life. Capillary blood sampling in the neonate is best performed on the plantar aspect of the foot, especially on the medial aspect of the posterior third, as shown in Figure 78.1. A ‘blood spot’ is collected on to a thick filter paper card (Fig 78.2). The specimen can be conveniently sent by mail to a central screening laboratory. The following questions are usually considered when discussing the cost-effectiveness of a screening programme.

Neonatal screening programmes for hypothyroidism and phenylketonuria have been established in many countries. Both these disorders carry the risk of impaired mental development, which can be prevented by prompt recognition of the disease. Local factors, such as population mix, have led to the setting up of specific screening programmes. For example, the high incidence of congenital adrenal hyperplasia (1 : 500 live births) among the Yupik Eskimo was the stimulus for a screening programme for this disease in Alaska. In Finland, the incidence of phenylketonuria is low and neonatal screening is not carried out.

Disagreement on the benefits and risks of tests, the presence of public pressure and availability of funding are factors that continue to determine whether neonatal screening programmes are established.