Newborn Screening Tests

Baby undergoing newborn screening tests

Last Updated December 20th, 2021

What are newborn screening tests?

Newborn screening tests are conducted on babies that are a few days old. These tests help rule out the presence of metabolic, developmental, genetic, hormone or blood associated disorders, that are not apparent after the birth of the child. These tests enable healthcare providers to adopt preventive measures or begin treatment early to enable better outcomes.

Why are screening tests on newborns necessary?

Screening panels can check for the existence of at least 26 disorders and some exhaustive panel tests can investigate the presence of close to 40 disorders. Healthcare providers also conduct tests to check for hearing loss in new-borns as well as advice screening for critical congenital heart disease (CCHD).

The blood screening tests conducted on new-borns helps healthcare providers begin the treatment early, so there is a better prognosis of the condition. Below is a list of some of the disorders detected by the newborn screening tests.

  • Spinal muscle atrophy (SMA)
  • Glucose-6-phosphate dehydrogenase deficiency (G6PD)
  • Cystic fibrosis
  • Biotinidase deficiency
  • Galactosemia
  • Congenital hypothyroidism
  • Toxoplasmosis
  • Phenylketonuria (PKU)
  • Amino acid metabolism disorders
  • Congenital adrenal hyperplasia
  • Sickle cell disease
  • Fatty acid metabolism disorders
  • Human immunodeficiency disease (HIV)
  • Organic acid metabolism disorders
  • Haemoglobin disorders
  • Beta thalassemia
  • Severe combined immunodeficiency (SCID)

What are the alternative names for newborn screening tests?

Newborn screening tests are also known as the PKU test, infant screening test, and neonatal screening tests

What are some of the important newborn screening tests?

PKU is an alternative name given to the screening tests conducted on newborns and happens to be the first among other newborn screening tests. Phenylketonuria (PKU) PKU or Phenylketonuria is a genetic disease that impairs the body’s ability to metabolize a particular protein called phenylalanine. This condition requires early diagnosis and treatment as it can cause deficient intellectual development.

Congenital hypothyroidism

At birth, some babies are born with deficient levels of the thyroid hormone, which can adversely affect the mental development and growth of the baby.


This is a genetic disorder where the baby is unable to metabolize galactose. Treatment is needed immediately as galactosemia can be potentially life-threatening. Symptoms of this condition may begin to show in the baby about 2 weeks post-delivery.  

Sickle cell disease

If undetected, it can trigger chronic anemia in babies. If diagnosed early through blood tests, treatment can help offset the risk of infections, stroke and blood clots.

Maple syrup urine disease

A genetic disorder that occurs in babies where they are unable to process amino acids (parts of protein). Therefore, the urine of the baby has a distinct odour much like the maple syrup. This is a serious life-threatening disease and can cause paralysis and disability even after treatment.


Is a genetic disorder that can hamper the baby’s intellectual development. It can also lead to disease of the bone or trigger the formation of blood clots. This condition arises due to the deficiency of a particular enzyme that is necessary to help digest methionine, which is an amino acid.

Biotinidase deficiency

This is a genetic disorder where the baby has a deficiency of the enzyme called biotinidase. This enzyme assists in the metabolism of biotin, a B vitamin. This condition can cause an accumulation of acids in the organs and blood, disrupting the functioning of various systems in the body.

Congenital adrenal hyperplasia

This is a genetic disease affecting the adrenal glands. Babies that are victims of congenital adrenal hyperplasia (CAH) cannot produce an adequate amount of cortisol. The hormone cortisol helps the body during illness, times of stress as well as to regulate sugar levels, blood pressure, and energy. Untreated, this condition can adversely affect puberty associated hormones and the development of genitals.

Medium-chain acyl-CoA dehydrogenase deficiency (MCAD)

This pertains to abnormalities in the oxidation of fatty acids which can lead to life-threatening conditions such as sudden deaths during infancy. It can also cause intellectual disability.

Hearing loss

This is an important screening test as it is estimated that one out of 1000 newborn experience hearing loss.

Doctors also test newborns for congenital disorders such as cystic fibrosis and congenital toxoplasmosis.

A novel testing method named tandem mass spectrometry (MS/MS) is also being employed which is capable of spotting close to 30 disorders, all with a blood sample. This test can also detect metabolic disorders.

When is the newborn screening test conducted?

The newborn screening test can be conducted only after the baby has received 24 hours of breast milk or formula. Doctors prefer if the initial screening tests are followed with a second blood examination when the baby is about 2 weeks old.

Is there any special preparation required to perform this test?

There is no specific preparation for this test except that it is preferable to perform the test before the baby leaves the hospital after birth.

How is the test performed?

Blood tests

The blood sample, which consists of a few drops of blood, is drawn from the baby’s heel using a heel-prick. A special paper or a small vial is used to collect the blood sample from the spot. There are no side effects. There could be a bit of redness at the site of the prick, which will normalize in a few hours. Mothers should ideally hold the baby close and make skin-to-skin contact or breastfeed to keep the baby comfortable and calm during the test.

Hearing test

A microphone or a tiny earpiece is placed in the infant’s ear. In some cases, healthcare providers also use electrodes connected to the baby’s head. This is possible if the baby is asleep or is quiet. Usually, the baby feels no uneasiness or discomfort during this test.

CCHD screening

A tiny sensor is placed on the baby’s skin for a few minutes. This is connected to an oximeter. This device records the oxygen levels of the baby in the hand and foot. The baby does not feel any discomfort during the test. 

Are there any major risks in the newborn screening test?

There are no major risks to babies with new born screening tests.

How long does it take for the results of the test to be ready?

The results of the tests conducted for heart disease and hearing loss are available instantly after the test is completed.

The results of the blood tests will take about 5 to7 days to be ready.

How do I interpret the test results?

The normal value range may show a slight difference between testing laboratories. If the results are normal no further investigation is necessary. If the test results are positive, your healthcare provider may ask for more tests to validate the findings or rule out the presence of suspected medical condition(s).  Your doctor may also refer the child to other medical specialists for their opinion or to commence treatment. Treatment for detected medical conditions must begin soon for a better outcome. The form of treatment can be through medicines, supplements, restrictions on diet and special formula. Such babies also need to have regular follow up and close monitoring with their healthcare professionals.

What is the cost of newborn screening tests?

The price of newborn screening tests differs according to facilities and the geographical location. However, it may range from INR 1800 to 2000.


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