Newborn Screening 7 Parameters

The Newborn Screening 7 Parameters test is a preventive screening panel designed to identify selected serious endocrine, metabolic, enzymatic and inherited conditions shortly after birth. Many of these disorders are not visible during a routine physical examination, and an affected baby may initially appear healthy. Detecting an increased risk before symptoms develop can allow confirmatory testing and timely treatment.

This panel is commonly configured to screen thyroid-stimulating hormone, 17-hydroxyprogesterone, glucose-6-phosphate dehydrogenase activity, immunoreactive trypsinogen, total galactose, biotinidase activity and phenylalanine. These seven parameters provide preliminary screening for congenital hypothyroidism, congenital adrenal hyperplasia, G6PD deficiency, cystic fibrosis risk, galactosemia, biotinidase deficiency and phenylketonuria.

The exact marker composition may vary between laboratory programmes. Parents and clinicians should confirm the seven included parameters on the Focus Diagnostics requisition or final report before using this description for clinical decisions. Newborn screening is not a diagnostic test. An abnormal or borderline result indicates that prompt repeat or confirmatory testing is required.

Why Is Newborn Screening Important?

Babies affected by some inherited or metabolic disorders may not show symptoms during the first days of life. By the time feeding problems, vomiting, jaundice, seizures, poor growth, developmental delay or other signs appear, preventable injury may already have occurred.

Newborn screening aims to identify babies who have an increased likelihood of a selected disorder while intervention can still prevent or reduce complications. Depending on the condition, early management may involve thyroid hormone, dietary restriction, vitamin supplementation, avoidance of triggering medicines or foods, specialist monitoring or other treatment.

Most babies have normal screening results. A screen-positive result does not mean that the baby definitely has the disease. Screening methods are intentionally designed to identify babies who may need further evaluation, which means some unaffected babies will also be recalled.

What Are the Seven Parameters?

1. Thyroid-Stimulating Hormone

Thyroid-stimulating hormone, abbreviated as TSH, is used to screen for primary congenital hypothyroidism. In this condition, the thyroid gland does not produce sufficient thyroid hormone. Thyroid hormone is essential for brain development, growth and metabolism.

Most affected babies have no obvious signs at birth. Without timely treatment, severe thyroid hormone deficiency can impair growth and neurodevelopment. An increased newborn TSH result requires confirmation using appropriate serum thyroid tests and paediatric assessment. Prematurity, illness, birth stress, collection timing and iodine exposure may influence the screening value.

2. 17-Hydroxyprogesterone

17-Hydroxyprogesterone, commonly written as 17-OHP, is used to screen for congenital adrenal hyperplasia, particularly the common form caused by 21-hydroxylase deficiency. Congenital adrenal hyperplasia affects adrenal hormone production and may cause cortisol deficiency, salt loss and excessive androgen production.

Severe salt-wasting disease can become life-threatening during the early weeks of life. An increased 17-OHP result does not confirm congenital adrenal hyperplasia because premature, low-birth-weight, stressed or ill babies may also have higher values. Confirmatory hormone and electrolyte testing is required urgently when the screen is significantly abnormal.

3. G6PD Enzyme Activity

Glucose-6-phosphate dehydrogenase, abbreviated as G6PD, is an enzyme that protects red blood cells from oxidative damage. G6PD deficiency is an inherited condition that can cause red blood cells to break down after exposure to certain medicines, foods, infections or chemicals.

Affected newborns may develop significant jaundice and, in severe cases, complications from increased bilirubin. Early identification helps families avoid known triggers and seek prompt medical care for jaundice or haemolysis. A recent blood transfusion or a high proportion of young red blood cells may affect screening accuracy.

4. Immunoreactive Trypsinogen

Immunoreactive trypsinogen, abbreviated as IRT, is a pancreatic protein used as an initial marker in newborn screening for cystic fibrosis. Cystic fibrosis is an inherited condition affecting chloride transport and may cause thick secretions in the lungs, pancreas and other organs.

An elevated IRT result is not diagnostic. Prematurity, birth stress and other non-cystic-fibrosis factors can increase the value. Depending on the screening programme, a raised result may be followed by a repeat IRT test, sweat chloride measurement, CFTR genetic testing or specialist evaluation.

5. Total Galactose

Total galactose screening helps identify babies at risk of galactosemia, a group of disorders affecting the body's ability to process galactose. Galactose is produced when lactose in breast milk or standard infant formula is digested.

Classic galactosemia can cause feeding difficulty, vomiting, jaundice, liver dysfunction, infection and other serious complications shortly after milk feeding begins. A screen-positive result requires urgent evaluation. The exact analyte and method may detect different forms of galactose metabolism disorder, so the laboratory report must be reviewed carefully.

6. Biotinidase Activity

Biotinidase is an enzyme that helps the body recycle biotin, also known as vitamin B7. Biotinidase deficiency may interfere with the function of several biotin-dependent enzymes. Untreated disease can cause seizures, abnormal muscle tone, developmental delay, hearing or vision problems, breathing difficulty, skin rash and hair loss.

Early treatment with oral biotin can prevent many complications. A low screening enzyme activity requires confirmation because prematurity, illness, transfusion, collection conditions or specimen handling may affect the result.

7. Phenylalanine

Phenylalanine is measured to screen for phenylketonuria and related causes of hyperphenylalaninaemia. Phenylketonuria, commonly called PKU, is an inherited disorder in which the body cannot adequately convert phenylalanine to tyrosine.

Untreated accumulation can damage the developing brain. Early dietary management and specialist monitoring can support healthy development. Collection too early or before adequate feeding may reduce the chance of detecting an abnormality, while other metabolic or liver conditions may also increase phenylalanine.

When Should the Sample Be Collected?

A dried blood spot is commonly collected after the baby has completed approximately 24 to 48 hours of life and has started feeding. Many programmes accept collection within 24 to 72 hours after birth. The exact recommended timing should follow the laboratory and paediatrician's protocol.

If the baby is discharged before the ideal time, a sample may be collected early, but repeat screening may be required. Screening should not be abandoned because the ideal window was missed. Parents should contact the paediatrician or laboratory as soon as possible to arrange appropriate testing.

How Is the Sample Collected?

The test commonly uses a dried blood spot specimen. A trained professional warms and cleans the baby's heel, makes a small puncture using a sterile lancet and applies free-flowing drops of blood to designated circles on a special filter-paper card.

Each circle should be adequately and uniformly saturated from one side. Repeatedly layering small drops, pressing the card against the heel or collecting an insufficient quantity may produce an unsuitable specimen. The card must be dried horizontally away from direct heat, sunlight, moisture and contamination before transport.

Does the Baby Need to Fast?

No fasting is required. The baby should generally continue normal breastfeeding or formula feeding. Feeding before or during collection may help comfort the baby. Parents should not delay feeding solely for newborn screening.

Feeding history is still relevant because very early collection before sufficient milk or protein intake can affect selected metabolic markers. The collection card should record the baby's age, feeding type and sample time.

Information Required on the Screening Card

Accurate clinical details are essential for correct interpretation. The card may require:

• Baby's name or identification number.
• Date and exact time of birth.
• Date and exact time of sample collection.
• Gestational age and birth weight.
• Sex of the baby.
• Feeding type and feeding status.
• Prematurity or neonatal intensive-care admission.
• Blood transfusion details.
• Medications, steroids or parenteral nutrition.
• Parent and healthcare-provider contact details.

Missing or incorrect information can lead to inappropriate cut-offs, delayed follow-up or the need for recollection.

Special Situations Requiring Repeat Screening

Premature, low-birth-weight or critically ill babies may have temporary abnormalities unrelated to an inherited disorder. Conversely, illness and treatment may mask a condition. Repeat screening may be needed according to neonatal and laboratory protocols.

Blood transfusion can interfere with screening for G6PD deficiency and other blood-related parameters. Total parenteral nutrition may affect amino-acid results. Steroid treatment can influence 17-OHP. Dopamine and severe illness may affect TSH. Parents must inform the laboratory about these factors.

Twins and other multiple births require separate, correctly labelled specimens. If one baby has an abnormal result, the paediatrician determines whether the sibling also requires additional testing.

Understanding the Screening Result

Screen-Negative Result

A screen-negative result means that the measured markers were within the programme's screening limits. It substantially reduces the likelihood of the included conditions but does not guarantee that the baby is unaffected. Screening methods do not detect every variant or every affected baby.

Parents should still seek medical assessment if the baby develops poor feeding, repeated vomiting, excessive sleepiness, seizures, breathing difficulty, unusual jaundice, abnormal movements, poor weight gain or developmental concerns.

Borderline or Repeat-Sample Result

A borderline result means the marker is close to the laboratory's action limit or the specimen cannot be interpreted confidently. A repeat dried blood spot or venous blood sample may be requested. Prompt recollection is important even when the baby appears healthy.

Screen-Positive Result

A screen-positive result indicates an increased possibility of a particular condition. It is not a confirmed diagnosis. The paediatrician may arrange disease-specific biochemical, enzymatic, molecular or genetic testing.

Some results require same-day clinical review because conditions such as salt-wasting congenital adrenal hyperplasia or classic galactosemia can deteriorate rapidly. Parents should follow recall instructions immediately rather than waiting for symptoms.

Possible Confirmatory Tests

Depending on the abnormal marker, follow-up may include:

• Serum TSH and free thyroxine.
• Serum 17-OHP, cortisol, electrolytes and adrenal testing.
• Quantitative G6PD enzyme analysis.
• Sweat chloride and CFTR genetic testing.
• Galactose-1-phosphate uridyltransferase activity and galactose metabolites.
• Quantitative biotinidase enzyme activity.
• Plasma amino acids and quantitative phenylalanine.
• Targeted molecular genetic testing.

The exact confirmation pathway is selected by the paediatrician or metabolic specialist.

What the Panel Does Not Include

This seven-parameter blood panel does not represent every component of comprehensive newborn screening. It does not replace newborn hearing screening, pulse-oximetry screening for critical congenital heart disease or a complete physical examination.

It also does not test for every inherited, chromosomal, metabolic or neurological condition. Expanded newborn screening panels may include additional amino-acid disorders, organic acidemias, fatty-acid oxidation disorders, haemoglobinopathies, spinal muscular atrophy or other conditions.

Benefits and Limitations

The principal benefit is early risk identification for serious but potentially manageable disorders before symptoms become apparent. One dried blood spot can assess several markers, and early recall can reduce preventable illness, neurodevelopmental injury or death.

Limitations include false-positive, false-negative and borderline results. Collection timing, prematurity, illness, feeding, transfusion, medication, parenteral nutrition and specimen quality may influence results. The test is a screen and cannot replace confirmatory diagnosis.

Newborn Screening at Focus Diagnostics

The NEWBORN SCREENING 7 PARAMETERS panel is available under the pathology and bio-chemistry department at a listed price of ₹2,500. Parents should confirm the exact seven included markers, ideal collection time, dried blood spot requirements and expected reporting time while booking.

Provide accurate birth, feeding, transfusion and treatment details. Ensure that the paediatrician and parents' current contact information is recorded so urgent recall results can be communicated without delay.

Important Instructions for Parents

• Do not fast the baby for sample collection.
• Prefer collection after 24 hours of life unless earlier testing is medically necessary.
• Disclose prematurity, transfusion, illness and current treatment.
• Respond immediately if a repeat or confirmatory sample is requested.
• Seek urgent care if the baby is unwell, regardless of the screening result.

Medical Disclaimer

This information is intended for general education and does not replace paediatric advice. Newborn screening identifies increased risk and does not independently diagnose or exclude disease. Any abnormal, borderline or unsuitable result requires timely follow-up according to the paediatrician's instructions.