Baby Pain Measurement Tools Fall Short of Medical Standards – ScienceBlog.com

The methods doctors and nurses rely on to assess pain in newborn babies lack solid scientific backing, according to an extensive review published this week in the Cochrane Database of Systematic Reviews.

Researchers at the Karolinska Institute found that none of the 27 clinical rating scales examined—tools used by medical professionals to gauge pain in infants who cannot verbally communicate—meet the rigorous validation standards expected in modern medicine.

“Over 70% of rating scales in this review did not assess content and structural validity, and both these factors are essential when selecting a measurement instrument,” said Kenneth Färnqvist, physiotherapist and PhD candidate at the Department of Molecular Medicine and Surgery at the Karolinska Institute in Sweden.

The findings raise concerns about the care of the estimated six to nine percent of newborns who require admission to neonatal intensive care units worldwide. These vulnerable patients often endure multiple painful procedures daily as part of their medical treatment.

The international research team analyzed 79 studies involving more than 7,000 infants across 26 countries. Most troubling was the discovery that current methods might be leading to either over-treatment or under-treatment of pain.

Unlike adults who can describe their discomfort, medical staff must rely on physical cues from infants, such as facial expressions, body movements, and vital sign changes. For premature babies, the challenge is even greater.

“It is important to remember that clinical rating scales are only surrogates for pain measurement,” noted Roger F. Soll, Professor of Neonatology at the University of Vermont, who contributed to the study. “Given the uncertainty highlighted in this review, clinical staff should avoid relying too heavily on the rating scales currently in practice and instead strive to decrease painful procedures as much as possible in this vulnerable population.”

The situation becomes even more complicated with premature babies, who typically have a reduced ability to display obvious pain behaviors due to their developmental immaturity. Similar limitations exist for infants who are sedated or critically ill.

The review’s timing is significant as neonatal care advances globally. With improved survival rates for extremely premature infants, accurate pain assessment becomes increasingly critical for preventing potential long-term neurological consequences.

Despite these concerning findings, researchers see an opportunity for progress. Emma Persad, doctor and PhD candidate at the Department of Women’s and Children’s Health at the Karolinska Institute, envisions this as a catalyst for change.

“This is our chance to unite clinicians and methodologists in developing a rigorously validated scale from scratch, one that meets all necessary checks before implementation in research and practice,” Persad said. “We look forward to beginning this impactful work and the implications it will have on assessing and managing neonatal pain worldwide.”

In the meantime, experts advise medical professionals to exercise caution when interpreting results from current pain assessment tools and to focus on minimizing painful procedures whenever possible.

The research represents one of the most comprehensive examinations of neonatal pain measurement to date. Its findings suggest that while modern medicine has made remarkable advances in caring for our youngest patients, significant gaps remain in understanding their suffering.

The full review, titled “Clinical rating scales for assessing pain in newborn infants,” was published April 14, 2025, and includes contributions from researchers in Sweden, Norway, Greece, the United States, Italy, and the United Kingdom.