Neonatal heel prick

The neonatal heel prick is a common procedure for taking a blood sample from the heel of newborn infants.

The blood samples can be used for a variety of tests, including:

• Thyroid stimulating hormone (TSH) to detect hypothyroidism and hence prevent cretinism.
• Trypsin to detect cystic fibrosis.
• Detection of phenylketonuria, an enzyme deficiency that can impair brain development.

Other potential tests include:

• A test for galactosemia

With genetic tests becoming more common, a wide variety of tests may use the blood drawn by this method. Many neonatal units (SCBUs) now use this method to carry out the daily blood tests (blood count, electrolytes) required to check the progress of ill neonates.