A newborn screening test is done within the first 24-48 hours after your baby is born. It’s an important way to detect hidden disorders in a newborn even before he/she shows obvious symptoms.
While it is a routine test, any abnormalities in the results can send a wave of panic among parents. But before you get all worked up, here’s something you need to know: an abnormal newborn screening result does not always mean that your baby has a disease.
Newborn screening is designed to identify babies who may need further evaluation. It is a screening test and not a diagnosis. After the test, the next step usually involves repeat or confirmatory testing to find out what the result actually means.
In this blog, we’ll take a deep dive into the topic to help new parents understand what abnormal results can mean and what steps they should take to ensure their child has a healthy life ahead.
So keep reading!
What Does an Abnormal Newborn Screening Result Mean?
Newborn blood-spot screening looks for markers associated with certain genetic, metabolic and endocrine conditions. Depending on the laboratory and screening programme, a result may be described as normal, borderline or out-of-range.
An out-of-range result means that one or more measured markers need further investigation. It does not confirm that a disorder is present. Depending on the finding, your baby may need another blood sample, additional laboratory tests, or an evaluation by a specialist.
Why Can a Newborn Screening Result Be Abnormal?
There are several reasons a screening result may be outside the expected range.
The timing of the sample can affect some results.2 Prematurity, low birth weight, blood transfusions, and certain medical treatments can also influence newborn screening results. One important example is total parenteral nutrition (TPN), which can raise amino-acid levels and lead to false-positive findings in tandem mass spectrometry-based metabolic screening.
The blood sample itself also matters. Collection, storage, and processing need to be done correctly, and samples collected at an unsuitable time may need to be repeated.
What Happens After an Abnormal Result?
The next step is follow-up testing.
Depending on the suspected condition, a doctor may repeat the newborn blood-spot screen or order more specific diagnostic tests. For suspected metabolic disorders, these can include plasma amino-acid analysis, acylcarnitine analysis and urine organic-acid testing. Additional biochemical or genetic testing may also be needed in some cases.
Some abnormal results require quicker action than others. This is because certain metabolic disorders can become serious before a baby develops obvious signs of illness.
Does an Abnormal Result Mean My Baby Has a Disorder?
Not necessarily.
A screening programme is designed to identify babies who might have a condition, so some babies who receive an out-of-range result will later be found to be healthy. This is known as a false-positive result. Further testing is what helps distinguish a true positive from a false positive.
The opposite is also possible: a normal screening result cannot rule out every medical condition. Newborn screening only covers the conditions included in that particular panel, and a baby who later develops concerning symptoms still needs medical evaluation.
So, an abnormal report should be taken seriously, but it should not be treated as a diagnosis.
Where Does Comprehensive Metabolic Screening Fit In?
Some expanded newborn screening panels use tandem mass spectrometry (TMS). This technology can analyse multiple metabolites from a single dried blood-spot sample and is used to screen for groups of inherited metabolic disorders, including amino-acid, organic-acid and fatty-acid oxidation disorders.
For parents considering broader screening, CP 510-LS (TMS 62) by LifeCell Diagnostics is a comprehensive newborn screening option. It includes 62 tests and covers both core & extended Inborn Errors of Metabolism. The results come within 2 days, enabling early diagnosis and lifestyle interventions, preventing irreversible neurological and metabolic damage.
What Should Parents Do After an Abnormal Report?
Start by speaking to your baby’s paediatrician or the healthcare professional who arranged the screening. Ask which marker was flagged, what condition it may be associated with, and what follow-up test is recommended.
Also share relevant details about your baby’s birth and early care, particularly prematurity, low birth weight, transfusion or TPN, as these factors can affect how some screening results are interpreted.
Most importantly, do not skip the recommended follow-up. When a condition is genuinely present, early diagnosis can give doctors an opportunity to start treatment or monitoring before complications develop.
The Bottom Line
An abnormal newborn screening result is a reason to investigate, not a final diagnosis.
Your baby may simply need a repeat screen or further testing. In other cases, follow-up may confirm a metabolic or other condition that needs specialist care. What matters is completing the recommended evaluation promptly and understanding the result in the context of your baby’s health and history.
