Most babies are born looking perfectly healthy. A few, though, have a body that cannot break down certain proteins or fats properly, because of an inherited change in a gene. Without treatment, substances can build up quietly and harm the brain. The newborn heel-prick test is there to catch these conditions early.
What is the heel-prick test?
A few drops of blood are taken from your baby’s heel in the first days after birth, usually between day 3 and day 7. The drops go on a special card and are tested in a laboratory.
The test looks for a group of inherited metabolic conditions, including:
- Maple syrup urine disease (MSUD): the body cannot break down some protein building blocks. Urine may smell like burnt sugar.
- Organic acid conditions: acids build up in the blood and can make a baby very unwell.
- Urea cycle conditions: ammonia builds up in the blood and affects alertness and breathing.
- Phenylketonuria (PKU): a protein building block builds up and can affect learning if not treated early with a special diet.
Warning signs in the first months
If a condition is not picked up by screening, a baby can become suddenly unwell, often after feeds start or during a mild cold. Call your doctor urgently if your baby:
- is unusually sleepy and very hard to wake for feeds;
- keeps vomiting;
- has an unusual smell to the urine or body;
- is breathing fast and deeply;
- has a seizure, or becomes very floppy or stiff.
Acting early
Finding the condition quickly means treatment can start straight away to protect your baby’s brain. Depending on the condition, this can include:
- A special medical formula that replaces some normal protein for a while.
- Supplements such as carnitine or certain vitamins that help the body cope.
- A sick-day plan so you know exactly what to do when your baby has a cold or tummy bug.