What is Newborn Screening

A few days after your baby is born, you will (if you live in the United Kingdom) be visited either by a midwife or a health visitor.  During this visit, your baby will most likely have a ‘heel prick’ of ‘blood spot’ test done.

The screening process is intended as a diagnostic tool and is therefore not 100% accurate.  The screening process is used only to determine the likelihood of your baby having any of the conditions tested for (listed below).  A result on the test which is not ‘negative’ does not mean that your child has been diagnosed with one of the conditions, it simply means that there is a possibility of the condition and further testing would need to be done.

In order to perform the test, the midwife or health visitor will prick your baby’s heel using a small sharp instrument, and will squeeze out five spots of blood onto a piece of card.  The midwife then sends these samples away to be tested.

Of course, the heel prick isn’t particularly pleasant for your baby, but it is over quickly, and in five minutes your baby will most likely have forgotten about it.  Your baby will probably have a little plaster on his/her foot, which can be removed in 10-15 minutes.  To make the heel prick easier for your child, ensure that he/she is comfortable when the test is done and comforted quickly afterwards.

Each blood spot is used to test for a different rare but serious condition, as follows;

1.    Phenylketonuria – 1 in 10,000 babies will be diagnosed with Phenylketonuria in the United Kingdom.  This is an inherited condition, which results in the child not being able to process a substance called phenylalanine.  Treatment revolves around the child having a special diet which will enable them to lead an ordinary life.  Failure to diagnose and introduce the special diet could reduce in your baby being permanently mentally disabled.

2.     Congenital Hypothyroidism – 1 in 4,000 babies are diagnosed with congenital hypothyroidism in the United Kingdom.  Early diagnosis allows the baby to be treated with thyroxine tablets in order to make up for the lack of thyroxine their body has naturally.  Failure to diagnose and treat early may result in permanent mental and physical disability.

3.      Sickle Cell Disorders – 1 in 1,900 babies born in the UK will be diagnosed with sickle cell disorders.  Early diagnosis allows early treatment using antibiotics, immunisations and parent education.  Failure to diagnose and treat early results in a condition where the red blood cells become sickle shaped and get stuck in the small blood vessels.  This illness can be painful and damaging to the body, can result in infection and can even be lethal.

4.     Cystic Fibrosis – 1 in 2.500 babies are born with cystic fibrosis in the United Kingdom.  It is an inherited condition which effects the digestion and lungs, resulting in the baby having frequent chest infections and insufficient weight gain.  Early diagnosis and treatment with a high energy diet, physiotherapy and medicines would help the baby lead a much healthier and longer life, although they might still become ill, the effects of this illness can be lessened.

5.     Medium Chain Acyl-CoA Dehydrogenase Deficiency (MCADD) – 1 in 10,000 babies are born with MCADD in the United Kingdom.  This is an inherited condition resulting the body not being able to break down fats to make energy.   Early diagnosis allows the caregiver to ensure the child is eating a good diet in order to prevent serious illness and even death.  Also, through early diagnosis and treatment the child can develop normally.

Depending on where you live in the UK and the agreed process for that area, the results of the test will most likely be sent to you by post before your baby is six weeks old.  If you have not received your results by post, your health visitor should be able to give you this information at your 6 week visit. 

If any of the tests’ outcomes are possibly positive, you will be contacted as soon as possible (usually before your baby is three to four weeks old) so that further tests can be taken and if necessary treatment can be arranged.

The screening process is not mandatory and you can tell your midwife or health visitor if you would prefer to not have the tests done.  However, for the sake of a five minute heel prick, the benefits of early testing far outweigh the potentially lethal results if any of the conditions are not diagnosed early enough.