Pezinho Test: what is it, when to do it, detectable diseases


What is the heel prick test?

The heel prick test is a mandatory test for all newborns, which must be performed after the first 48 hours of life. With a small sting in the heel, it is possible to find various diseases and treat them in time, before they affect the baby’s development.

The test consists of obtaining and analyzing a blood sample from the newborn in order to detect metabolic, infectious, congenital and / or genetic diseases. It must be done 48 hours after birth, so that it is not influenced by the mother’s metabolism. In addition, the baby needs to feed first, ensuring more accurate results.

The two main diseases examined in the test are Phenylketonuria and Hypothyroidism .

Foot test in SUS

Also known as basic screening , the foot test in SUS is mandatory and free, available in all states.

It can detect six diseases:

  • Congenital hypothyroidism;
  • Phenylacetonuria;
  • Sickle cell anemia;
  • Biotinidase deficiency;
  • Cystic fibrosis;
  • Congenital adrenal hyperplasia.

There are other, more comprehensive tests that detect a greater number of diseases, but are paid for.

How is done?

At the hospital, the mother stays with the baby during the exam. The nurse asepsis the location of the bite (usually the heel) and performs a puncture with a lancet, a type of special needle that pierces superficially. Due to the high vascularization of the site, blood flows easily, making it possible to perform the exam.

The blood is collected on a filter paper, which is sent to the laboratory with data identifying the mother and the collection point. On this paper, there are demarcated circles, in which a drop of blood must be dripped on each one. The paper must not come into direct contact with the baby’s skin.

In the laboratory, disease analysis and detection takes place. If any pathology is found, the hospital contacts the mother, and the baby must perform further tests to confirm the problem.


To lessen the pain

Babies feel less pain and cry less when in the kangaroo position, being breastfed by the mother and wearing only a diaper. This procedure must start three minutes before the bite, and the position must be maintained during the collection and three minutes after the exam.

Test on the arm

Some hospitals perform the test on the baby’s arm, as it hurts less and does not leave the purple mark on the heel.

The test on the arm is no less effective than the test on the little foot. What really matters is collecting the baby’s blood sample.

Why take the test?

The test is mandatory and must be performed to prevent complications of diseases that, at the birth of the child, are asymptomatic.

If these diseases are not diagnosed and treated in advance, the child will be susceptible to numerous problems, which can be serious and irreversible. Malformations are one of those evils that, once present in the body, are incurable.

When to do the heel test?

The ideal is to perform the exam 48 hours after birth, until the 5th day of the baby’s life. If the test is done before this minimum time, it is necessary to repeat it, ensuring greater precision in the results.

It is important to confirm, after delivery, if the baby’s foot test has already been done. Sometimes, the test is carried out while still in the hospital, without the mother being aware of it. Therefore, confirm with the doctors that the test has been done and, if so, inquire about the date of delivery of the results.


There are no contraindications for any type of examination.

How to prepare

Find out more about the hospital in which you intend to have the baby, to know the tests offered there and the costs of each one.

It is essential to breastfeed the baby before the exam, as this facilitates the diagnosis of some diseases.

Other types of tests

In addition to the basic test, there are paid tests that can detect a greater number of diseases. It is always good to ask for information about each one and about which pathologies he can identify.

Examples of tests and the number of diseases tracked by each:

  • More: 10 diseases;
  • Expanded: 20 diseases;
  • Plus: 23 diseases;
  • Master: 28 diseases;
  • Expanded: 46 diseases;
  • Super: 48 diseases;
  • Complete: More than 50 diseases screened.

How do I choose the right foot test for my baby?

The doctors responsible for monitoring the pregnancy are better able to clarify this issue. Talk to your hospital / maternity pediatrician and ask what is the best test for your baby.

To determine the most appropriate test, the doctor usually evaluates how the pregnancy went, what diseases tend to affect the population of your region and the baby’s family history. Also remember that there are paid tests, mainly in private clinics.

Find out about the values ​​of each test before starting the procedure.


The result can take a week or even a month to be ready, and it is usually picked up at the test site. Some can also be withdrawn over the internet.

There are two types of result: normal and altered. The normal is that in which no disease was found in the baby, while the altered one shows which or which diseases were observed.

Normal result

In the normal result, the family is not usually communicated by phone. Even so, it is recommended to repeat the test to ensure the baby’s health. Even extended tests with normal results must be redone, as there is a possibility that some disease has not yet been discovered.

Result changed

In an altered result, the family is contacted by phone to repeat the exams, confirming or not the presence of signs of illness. If confirmed, the child will be referred for further tests, more detailed, before any conclusion. The sweat test is one of them, which can more accurately detect cystic fibrosis , an incurable disease that, if treated early, guarantees a better quality of life for the child.

If, after the detailed tests, there is confirmation of illness, the doctor will give more specific instructions and appropriate treatments for each case, including different diets, if necessary.

Detectable diseases

The purpose of the heel prick test is to detect serious illnesses that can be treated at an early stage. Some of them are:


Disease that causes deficiency of the enzyme phenylalanine hydroxylase, responsible for the breakdown of phenylalanine present in various foods, causing excess of this substance in the blood. This excess becomes toxic and can cause cognitive delay (intellectual disability).


The galactosemia is characterized by difficulty in the metabolism of a milk sugars: galactose. This is not a lactose intolerance (formed by glucose and galactose), but a genetic disease that can be lethal if not treated early.


Insufficiency in thyroid hormone, can cause cognitive delays, mood disorders and failure in physical development.

Congenital adrenal hyperplasia

Characterized by abnormalities in the adrenal glands, adrenal hyperplasia impairs the production of cortisol and aldosterone, essential hormones for the body. This condition can alter the external genital development of babies, in addition to causing exaggerated loss of salts and elevation of potassium. Severe conditions can lead to death.

Cystic fibrosis

Genetic disease that causes deficiency in the transport of chlorine and sodium in cell membranes. This causes the production of thick mucus that can obstruct the lungs, in addition to causing insufficiency in the pancreas, impairing digestion.

Biotinidase deficiency

Biotinidase is the enzyme responsible for the separation of vitamins B7 and B8 from food, so that it can be used by the body. When there is a deficiency of this vitamin, there are problems in the metabolism of certain fats, carbohydrates and proteins and, when left untreated, it can lead to intellectual deficiency.

Congenital toxoplasmosis

The toxoplasmosis congenital is an infectious disease that is passed from mother to baby during delivery. It can cause severe sequelae, such as inflammation of the retina and neurological problems.

G6PD deficiency

The deficiency of the enzyme glucose-6-phosphate dehydrogenase (G6PD) makes the red blood cell membrane more unstable, facilitating its destruction. Thus, there is a greater risk of hemolytic anemias.

Congenital rubella

Caused by the togavirus, congenital rubella can leave irreversible sequelae such as glaucoma , cataracts , cardiac malformation, growth retardation, among others.

Sickle cell anemia

Due to a genetic defect, red blood cells have a sickle shape in sickle cell anemia . This shape causes them to become trapped in blood vessels, causing poor blood distribution throughout the body.

Chagas disease

When passed by the mother during pregnancy, Chagas’ disease can cause anemia , pain, fever , heart and bone problems.


Considered incurable, the disease leads to impairment of the immune system.

Risks of the heel prick test

The test is safe for the baby.

On the other hand, it is risky not to perform the test, as this can affect the health of the newborn. It is also dangerous to perform the test without aseptic techniques, that is, without the necessary hygienic preparation to avoid possible contamination.

Common questions

Does the foot test hurt the baby?

The puncture is almost painless but, as it is a new sensation for the baby, he cries. The heel is a region full of blood vessels, which facilitates blood collection and reduces pain. The arm test is also an alternative, as the site is usually less painful and the procedure is quick, being as efficient as the traditional one.

I forgot to do the heel test, now what?

If the test was not performed within the recommended period, it is necessary to do it as soon as possible, preferably within 30 days after the child’s birth. The risk of false diagnoses, however, is greater in these cases.

It is worth remembering that the foot test is only the basic screening, not being able to diagnose any disease. For real confirmation, more detailed and complete exams are needed.

How much do the tests cost?

The basic test is free, funded by SUS and available in all hospitals. Expanded tests, on the other hand, are paid for, sold on private networks and the price varies according to the number of diseases detected. Fortunately, many of these tests already have their value included in health plans.

The price range of the tests is 200 to 350 reais, but some are an exception to the rule and may charge a higher or lower amount for the exam.

Private networks offer the expanded test called “Mais”, which diagnoses 4 diseases in addition to those mentioned in the basic version, which are: galactosemia, congenital toxoplasmosis, leukinosis and G6PD deficiency. Another test is the “Super”, one of the most complete in Brazil, which can detect around 48 diseases, costing R $ 425.00 reais.

And in case of home birth?

Talk to the medical team, as they will indicate which is the best test for your baby and where to perform it. You can do the test outside the home until the baby’s fifth day of life, or request a home collection. Home collections, however, are paid services.

I was discharged before 48 hours, what to do?

It is important that you have the test after 48 hours of life, until the fifth day after the baby is born. If you are discharged before this time, ask for a referral to take the free basic exam.

The heel prick test is essential for your baby’s life. Do not leave it for later! Take the foot test at the nearest health unit now. If you have questions, contact us.