Newborn Baby Screening - Types & How it is Done

Newborn Screening Tests

A newborn baby is sensitive and has to adapt to its new environment after being in the safety of the womb for nine months. Recent developments in science and medicine have allowed doctors to monitor the condition of a baby right from the moment when the first organs start to take shape. However, it is very important to have a screening done immediately after the birth of the child in order to ensure good health and early detection of any medical conditions.

Video: Newborn Screening Tests

What Is Newborn Screening?

A newborn screening test is a simple test performed on newborn babies to check for potentially fatal or harmful disorders which cannot be otherwise detected at birth. The screening is performed soon after birth and sometimes before leaving the hospital. The process is simple and includes a blood screening as well as hearing screening tests.

Why Is It Important to Have Baby Screening?

The importance of newborn screening is that it helps in early detection of any adverse condition that the baby might be suffering from which cannot be known otherwise. The Newborn screening results will allow doctors to take necessary action immediately to safeguard the health of the child.

Reasons Why Baby Is Screened

The most important reason for newborn screening for babies is the early diagnosis of a medical condition so that in time care and treatment can be provided to the child. This will help to ensure that the child’s development is healthy and normal.

What Disorders Are Included in Newborn Screening

The infant screening test usually looks for a wide range of disorders which includes the following:

  • Phenylketonuria (PKU): PKU is a metabolic disorder which results in babies missing an enzyme required to process phenylalanine which is important for normal growth in kids. The PKU newborn screening can help detect over or underproduction of phenylalanine and treat the problem.
  • Sickle cell disease: This disease affects the red blood cells making them sticky, fragile and stiff. This condition restricts the movement of red blood cells in the bloodstreams which can cause damage to vital organs and make the baby prone to life threatening infection. This condition is usually genetically inherited. The newborn screening test can detect this disease and the doctors can provide suitable treatment to the baby.
  • MCAD deficiency: MCAD is an enzyme which assists in the breakdown of fatty acids in the body and a deficiency of the MCAD enzyme can lead to low blood sugar level in the baby. It is important to ensure that kids with this deficiency have nutritious food at regular intervals and do not skip meals.
  • Tyrosinemia: tyrosinemia is a condition that can lead to intellectual disability, liver problems or even liver failure and treatment for the same requires a special diet or at times a liver transplant.
  • Biotinidase Deficiency: Biotinidase is an enzyme which recycles biotin, a B complex vitamin which helps the body to convert food into energy and a deficiency of the same can cause loss of hearing, seizures, immune system deficiencies and even death. Babies who are detected with this deficiency can be given extra biotin as a safety measure.
  • Congenital Adrenal Hyperplasia (CAH): This disorder can have an adverse effect on genital development and lead to death due to loss of salt from the kidneys. The treatment for this condition is by giving supplements of the missing hormones.
  • Maple Syrup Urine Disease (MSUD): This disease results in the urine smelling like burnt sugar or like maple syrup due to the build-up of amino acids in the body. If not treated early, this can cause intellectual and physical disability in the baby and also lead to death.
  • Cystic Fibrosis (CF): Cystic Fibrosis exposes kids to lung diseases as it is a genetic disorder which has an effect on lungs and digestive system. There is no cure known for this condition and the treatment aims at prevention of any severe lung diseases via antibiotics and nutritional diet.

  • Severe Combined Immunodeficiency (SCID): Lack of B- and T-lymphocytes, a type of specialized white blood cells which help the body to fight infections causes this serious immune system disorder in the body. A weak immune system makes it difficult for the body to fight any infection causing viruses, bacteria or fungi making the baby susceptible to diseases and infections. Early detection of SCID can help in taking measures to strengthen the immune system.
  • Toxoplasmosis: Toxoplasmosis is an infection which is caused by Toxoplasma gondii, a tiny parasite that can live in human and animal cells and is mainly found in cats and farm animals. This infection can result in severe problems for a baby which include seizures, eye problems, intellectual disability or brain damage.
  • Galactosemia: This is a condition where the enzyme which converts glactose into glucose is missing in the baby. In such a condition, all dairy products must be removed from the baby’s diet.
  • Congenital Hypothyroidism: This condition results in babies not having enough thyroid hormone, causing slow brain development and growth. The baby can be treated with oral doses of thyroid hormone if the condition is detected early.
  • Hearing screening: It is important to get a newborn hearing screening test done within three weeks from the birth of your baby. Kids develop speaking and language skills early in their life and hearing play an important role in ensuring the development of these skills. Early detection of hearing loss and treatment of the same can help the baby to have a normal intellectual growth.

Most of the diseases identified in the baby via newborn screening test can be corrected if action is taken by the certified professionals on a timely basis.

When Does the Neonatal Screening Happen?

Infant metabolic screening is usually performed immediately after the birth of the child. The right time to do a blood test is between 24 to 48 hours of birth as many conditions might go undetected if the blood sample is drawn before 24 hours and it might get too late to take corrective action if the test is performed after 48 hours. The baby might also need a second screening test when they are two weeks old to ensure accurate results.

List of All Newborn Screening Tests

A newborn baby is screened for over 50 medical conditions under the following category of tests:

  • Haemoglobinopathies: Test for identifying problems related to haemoglobin which include disorders like sickle cell disease, thalassemia etc.
  • Endocrine disorders: Screening for conditions which cause hormonal imbalances such as hypothyroidism.
  • Carbohydrate disorders: Tests for conditions such as lactose intolerance that affect carbohydrate metabolism.
  • Infectious diseases: Testing for the presence of infection-causing viruses and other antibodies.

The different kinds of tests include:

  • Blood test: This test is also called the heel stick test as the blood sample is drawn by pricking the baby’s heel. The blood sample is collected and placed on a filtered card that will create blood spots which are sent for testing.
  • Hearing screening test: There are usually two different sets of hearing test performed on the baby. These tests take about five to ten minutes and are safe for the child.
    • Otoacoustic Emissions Test (OET): With this test, the doctors try to determine whether the baby’s ears respond normally to sound.
    • Auditory Brain Stem Response (ABR): The purpose of this test is for evaluating the nerves that carry sound to the brain and how the brain responds to this sound. This test is performed by inserting miniature earphones into the ear and playing sound.
  • Pulse Oximetry Testing: The purpose of this test is to measure the oxygen level in the child’s blood which can help in identifying babies who have Critical Congenital Heart Disease (CCHD). The test is performed after the baby has completed 24 hours using a machine known as the pulse oximeter.

How Is Infant Screening Procedure Done?

The procedure for the metabolic screening test for newborns is simple and not time-consuming. Most tests are carried out within two days from the birth of the baby. The blood test is the only painful test as the blood sample is drawn by pricking the child’s heel. The parents can choose to be present when the test procedures are being carried out on the child.

In cases where the screening is performed within 24 hours from the child’s birth, it is recommended to get the tests redone again within one or two weeks.

How Should You Prepare Baby for the Screening?

Newborn screening procedures are simple and do not require any special preparation on the part of the parents or the baby. Most screening tests will happen before the mother and the child are discharged and in complete supervision of professional doctors.

It is advised to nurse/feed the baby before and/or after the procedure and ensure that the baby is comfortable and warm while the procedure is being carried out.

At the time of the blood test, parents might choose to hold and comfort the child while the sample is drawn out of the child’s heel as this will be painful. For other tests, it is best to put the baby to sleep so that necessary instruments can be easily attached to the baby with ease.

Does Newborn Screening Test Hurt Your Baby?

As mentioned before, the only test which will hurt your baby is the blood test. The blood sample is drawn out by making a small prick in the heel of the baby which might cause brief discomfort to the child. The prick heals quickly and leaves no scar on the child.

Hospitals have trained professionals to handle the baby and give maximum comfort. The parents can also choose to handle their baby while the test is being carried out.

Is Screening for Genetic Disorders Done?

The screening process will also include tests for identification of genetic and inherited disorders such as Cystic fibrosis, phenylketonuria, sickle cell disease, etc. Early detection of these genetic disorders will allow doctors to take precautionary measures to limit their effect on the child.

Test Reports

The test reports from the baby’s screening are usually sent out to the doctor within 2–3 weeks from the testing. Following are the usual test results from the screening process:

  • Screening Test – Negative

A negative or ‘in-range’ result means that all parameters tested for are in the normal range and there is no increased risk to the child. Normally, follow-up testing is not necessary for such situations.

  • Screening Test – Positive

A positive or ‘out-of-range’ report signifies that at least one of the test parameters are not within the normal range or failing. The parents are notified in case of a positive report. The positive report itself does not mean that the child is suffering from a disease, it is an indicator and requires further testing to diagnose the problem. Once the root cause of the problem is established, the doctor can suggest necessary corrective measures.

It is to be noted that the tests might not always be accurate and there is always a margin of error. There might also be rare cases where the report shows results as borderline. Such a situation may require further testing.

What If There Are Some Problems With the Baby?

In case the testing report is positive, the doctors may suggest further test procedures to diagnose the problem. Once the disease/infection is identified, the doctor will suggest the necessary treatment or diet plan which will help the baby recover from the condition.

Baby Screening and Homebirths

Irrespective of where the baby is born, it is very important to get the screening done. If you plan to deliver the baby at home or if your baby is born at home, you should book an appointment with your doctor/preferred hospital where this service is available. As the timing of the tests, especially blood test is very critical, it is ideal to have the appointment taken in advance on the basis of expected delivery date.

The necessary equipment for performing the tests might not be available in too many hospitals. Hence, it is important to identify and book a slot with the hospital in advance.

What If Your Baby Doesn’t Undergo Screening?

The chances of a severe disease or an adverse medical condition going unnoticed are high if the baby does not undergo the screening procedures soon after birth. Some of the medical conditions can also be life threatening and can result in abnormal growth or in some cases even premature death of the child.


1. Is PKU test same as a newborn screening?

Yes, these tests are the same and some doctors may use these words interchangeably.

2. Do parents have to ask for a screening?

Most hospitals will perform a screening test without having to ask for it specifically. However, the parents can ask to ensure that the procedure is being carried out in time.

3. Is it mandatory to get a baby screened at birth?

In India, it is not mandatory to get a baby screened at birth. However, it is advised to get the procedure done even if it is not mandatory.

Newborn screening is the perfect way to detect any health issues the baby may be facing and provide immediate help if needed. Early intervention helps nip several problems in the bud and is advised for all babies.

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