Few connections scare a family as much as the news that the newborn’s heel test was altered. But there is essential information that needs to be said right from the beginning: the heel prick test does not confirm the diagnosis.
What the heel prick test really evaluates
It is a screening test created to identify babies who may be at greater risk for certain diseases and who need further investigation.
In practice, this means that an altered result does not automatically mean that the child is sick. On the contrary: as the diseases being researched are rare, most positive results end up being false positives. In neonatal screening programs, around 1% to 2% of exams may show some initial change, but only a portion of these cases will be confirmed after investigation.
What happens when the exam is changed
When there is a change in the test, the result needs to be tracked quickly. Depending on the marker found, the baby may need to repeat the collection, undergo specific confirmatory tests or be referred to a specialist.
The urgency varies depending on the clinical suspicion.
Generally, the result is communicated to the responsible doctor or the hospital where the birth took place. As the test is usually ready between five and seven days after collection, many are already at home when the change appears. Therefore, neonatal screening services need to have efficient protocols to locate the family and guide the next steps.
In more delicate situations, where the rapid start of treatment can change the child’s prognosis, the screening program itself can actively search for the family to speed up care.
Why many results are not confirmed
There are several factors that can interfere with the heel prick test and increase the chance of a false positive.
This happens more frequently in seriously ill newborns, babies admitted to the neonatal ICU or using parenteral nutrition. Collections carried out very early can also alter some markers, especially in diseases such as congenital hypothyroidism and congenital adrenal hyperplasia.
Additionally, some samples need to be repeated because they were collected too early or in insufficient quantities.
Therefore, the heel prick test should always be interpreted as an initial stage of investigation – never as an isolated diagnostic confirmation.
When speed makes a difference
Even though we know that many altered results will be discarded later, every change needs to be taken seriously.
The purpose of newborn screening is to identify treatable diseases before symptoms appear. In several of these conditions, early diagnosis makes it possible to initiate interventions capable of avoiding neurological sequelae, serious metabolic changes and even risk of death.
In other words: the exam exists precisely to allow treatment to begin before the disease causes permanent damage.
The way you communicate also matters
In addition to the technical quality of the exam, there is an aspect that is often little discussed: the way this news is given to the family.
Receiving information that “the test was altered” without adequate explanations can generate immediate despair in parents, especially in the first days after birth, a period that is already naturally sensitive and emotionally intense.
Therefore, reception makes a difference
It is essential that the healthcare team clearly explains that the exam is a screening process, that the majority of cases are not confirmed as illnesses and that the next steps exist precisely to clarify the situation safely.
Communication needs to balance two things at the same time: reassuring without minimizing the importance of quick follow-up.
When the family understands the process, they are able to face this period with less guilt, less fear and more trust in medical advice.
The main message
An abnormal heel prick test should not be ignored, but it should also not be interpreted as a definitive diagnosis.
Most of the time, research shows that the baby is healthy. Still, rapid follow-up is essential because, in cases where the disease really exists, early diagnosis can completely change the child’s life.
*Text written by Dr. Alessandro Danesi, pediatrician and national Head of Pediatrics at Brazil Health (CRM 57351 – RQE 57526)
