The newborn screening

Newborn screening is one of the first tests performed on a newborn baby to detect whether he or she has certain health problems that may require specific care.

The first test performed on a newborn, before newborn screening, is the Apgar test. It is carried out just one minute after the baby is born, and is used to analyse the baby’s adaptation and vitality, assessing several points:

• Respiration
• Heart rate
• Muscle tone
• Skin colour
• Reflexes

Each parameter is assigned a value, which can be 0, 1 or 2. The sum of all parameters will be a number ranging from 0 to 10.

The parameters are measured again after five minutes, following the same procedure. In this way, two total values are obtained, which are expressed in the X/X format. For example: 7/9, 8/5, etc.

A score of 7 or higher usually shows a good adaptation to the external environment after birth.

Newborn screening, 48/72 hours after birth

The newborn screening test aims to detect any health problems in the newborn as early as possible.  Within newborn screening, the so-called “heel prick” is crucial for the baby’s health. It is aimed at early identification of rare metabolic and genetic diseases, in order to implement medical care, dietary adaptation or lifestyle habits focused on minimising the impact of the pathology on the child’s life.

This test is usually performed on the newborn at the hospital of birth, the parents are informed and the child is taken to the neonatology unit, where the sample is taken. To collect the sample, a small puncture is made in the heel with a lancet (hence the name of the test!) and the blood is soaked in absorbent paper.

Between one and two out of every 1,000 apparently healthy newborns have a congenital metabolic disorder. In this type of disease, early diagnosis is key, as in many cases it is possible to adapt the medical care of the child before the disease causes irreversible consequences, avoiding or mitigating the development of the pathology through medication and/or a specific diet according to the child’s needs.

What diseases does newborn screening test for?

Newborn screening tests for certain biochemical parameters in the blood which, in the case of disease, are often found to be altered.

False positives are common because the type of sample may not reflect the real concentration of the parameters in the blood. Therefore, if there is a positive result, it is necessary to confirm or rule out this result by means of a genetic test.

Why is genetic testing necessary?

Each gene carries instructions for making a protein with a function in the body, such as metabolising fructose, metabolising phenylalanine etc. If there is an alteration in a gene (mutation), the protein it gives rise to may not form or function properly, resulting in altered blood levels that are detected by the heel prick test.

Neonatal screening is covered by social security, however, there is no consensus between autonomous communities to carry out the same analysis, although work is being done to achieve this. In any case, screening for at least these 7 diseases is compulsory in any autonomous community, as stated by the Ministry of Health:

• Congenital hypothyroidism (CH)
• Phenylketonuria (PKU)
• Medium-chain fatty acid acyl CoA dehydrogenase deficiency (MACDD),
• Long-chain fatty acid 3-hydroxy acyl CoA dehydrogenase deficiency (LCHADD)
• Glutaric aciduria type I (GA-1)
• Cystic fibrosis (CF)
• Sickle cell disease (SCD)

Although not mandatory, screening for congenital hearing loss is also recommended.

Is the heel prick test enough?

The heel prick is a necessary test, but it screens for a limited number of diseases. It is important for parents to know that there are tests that allow screening for a larger number of diseases that appear during childhood, to complement these results:

• Biochemical analysis: there are biochemical analyses that use the same methodology as the heel prick, but which screen for more than thirty diseases, therefore much more extensive.
• Genetic testing: genetic analyses focus on analysing the genes involved in the origin of this type of disease. These are molecular tests that provide very accurate results, with a very low false positive rate, and potentially allow up to 390 diseases to be analysed. In contrast to biochemical tests, it is not necessary to take blood from the baby, but only a sample of the baby’s saliva or a mouth swab.

Early detection of hearing loss

As we have just mentioned, this test is only covered by social security in some autonomous communities. It is carried out during the baby’s first month of life and its aim is to detect hypoacusis, i.e. a diminished hearing capacity.

If it is positive, it is necessary to assess whether the baby will be given a pharmacological, surgical or speech therapy approach.

To perform this test, headphones are placed on the baby while it is asleep or very relaxed, to see its response to certain sound stimuli.

Newborn screening options and results

Following the newborn screening programme of your autonomous community is essential to detect possible metabolic or genetic diseases that could have a great impact on the health of the newborn, however, the number of pathologies included in this type of analysis is limited.

It is important to know that there are tests that allow the neonatal screening analysis to be extended for parents interested in carrying out the most complete study possible. At Veritas we offer myNewborn, the test analyses more than 390 metabolic and genetic diseases that appear during the first years of life. If the result is negative (which occurs in approximately 90% of cases), it provides peace of mind, while if it is positive, you can take an early and specific medical approach to the child from day one, preventing the development of the pathology or reducing the impact on their life as much as possible.

Information is power and even more so when it comes to our children, that’s why we at Veritas have created a newborn genetic screening for early onset diseases. Get more info about myNewborn test here.