What a Newborn's Hearing Test Can — and Cannot — Tell You

Two 2026 studies from Nottingham explain why hearing loss in babies who needed intensive care is often a sign of something wider, and what that means for families

Babies who spend time in newborn intensive care are much more likely than other babies to have permanent hearing loss. Two studies published in 2026 by a research team in Nottingham found that the same illnesses that damage hearing often affect the rest of the body too, and that children with hearing loss are more likely to have other conditions identified by the age of two. Hearing loss, in other words, is often a signal rather than a stand-alone problem.

That framing matters because it changes what families should expect from follow-up. It is not a reason to be frightened. It is a reason to keep the appointments, ask questions early, and understand why the team may want to look at more than your baby's ears.

How newborn hearing testing came to be, and where it falls short

Not long ago, most children with permanent hearing loss were not identified until they were two or three years old, usually because they were slow to talk. By then the brain had already missed some of its best years for learning language. Newborn hearing screening — the quick test done in the first days of life — was introduced across most wealthy countries in the early 2000s and pulled the age of diagnosis down dramatically [1].

The test works well for healthy newborns. It works less cleanly for babies in intensive care. The screen measures how the hearing nerve responds to sound, and a baby who has recently come off a breathing machine, or who still has fluid in the middle ear, can fail the test without having permanent hearing loss at all. Intensive care nurseries have therefore always needed their own testing pathway, with repeat tests and specialist follow-up [2]. The professional body that sets standards for newborn hearing programmes responded by keeping a list of "risk factors" — severe jaundice, serious infection, certain medicines — that mean a baby should be re-tested or watched for longer [3].

A list, though, only says yes or no. It does not say how much risk a particular baby carried, or whether it was the jaundice or the infection that mattered. Later research showed that these risks stack up: it is the number of things a baby went through, more than any single one, that predicts hearing problems [4]. The Nottingham team's own earlier work found that how long a baby stayed in intensive care predicted permanent hearing loss better than birth weight did, and that hearing loss went hand in hand with developmental delay at two years [5]. The two 2026 studies pick up exactly where that left off.

The first study: reading the clues already in the chart

Babies in intensive care have blood tests every day. The first 2026 study asked a simple question: do any of those routine results predict which babies will later be found to have hearing loss? The researchers gathered every relevant study published between 2000 and late 2025 — 86 studies in all — and pooled the results where the numbers allowed [6].

Two themes stood out. The first was jaundice. Jaundice is the yellow colouring caused by a substance called bilirubin, which almost every newborn has to some degree and which is usually harmless. At high levels, though, bilirubin is toxic to the hearing nerve. Hospitals decide when to treat jaundice using a blood test called total bilirubin [7]. The review found something important: total bilirubin was a surprisingly weak predictor of hearing loss. A different measurement — the small fraction of bilirubin that is not stuck to protein in the blood, called "unbound" bilirubin — predicted it much better [6]. In the strongest study, babies who went on to develop hearing damage had roughly three times more unbound bilirubin than those who did not, even when their standard bilirubin result looked acceptable [8]. Standard bilirubin tests did not track hearing changes; the unbound measurement did [9].

There is a catch. Unbound bilirubin is a research measurement that most hospitals cannot yet order. What families can take from this is the underlying idea, which doctors already use: the same bilirubin number is more dangerous in a baby who is premature, infected, or unwell than in a healthy full-term baby. That is why two babies with the same test result may be treated differently.

The second theme was infection. Not all infections carried the same risk. Meningitis — infection of the lining around the brain — congenital cytomegalovirus (a common virus that can pass from mother to baby before birth), and serious fungal infections were all clearly linked to hearing loss. A positive blood culture on its own, without meningitis, was not [6]. Large studies in very premature babies bear this out: about 8 in 100 babies who had meningitis later had hearing loss, compared with 5 in 100 who had a bloodstream infection only, and 3 in 100 who had no infection at all [10].

The review also found that in babies cooled after a difficult birth, low blood sugar in the first hour of life and signs of strain on the kidneys and liver went along with hearing loss [11]. That is not really a story about ears. It is a story about a body that was under severe stress, with hearing being one of the places the damage shows.

The second study: what a hearing diagnosis predicts

The companion study followed 94 children who had confirmed hearing loss in both ears after intensive care, and compared each of them with a child of the same birth weight, gestational age and sex who had been in intensive care but did not have hearing loss [12].

At birth, the two groups looked the same. Doctors had recorded no more birth differences or physical anomalies in the babies with hearing loss than in the comparison group. By the two-year check-up, the picture had changed considerably. Roughly two-thirds of the children with hearing loss had at least one recorded condition affecting another part of the body, compared with about one-third of the comparison children. Most of the difference involved the nervous system. Children with hearing loss were also far more likely to have moderate or severe developmental delay at two years [12].

The researchers are careful about what this means. Part of the difference is probably because children with hearing loss get more attention: more brain scans, more specialist appointments, more genetic testing, so more gets found. Part of it is probably real — some conditions simply are not visible in a newborn and only become apparent as a child grows. And part may be that hearing loss and other differences share a common origin in how the body developed before birth. The study cannot separate these explanations, and its authors say so plainly [12].

What this means for your family

If your baby failed the newborn hearing screen, the first and most important point is that a failed screen is not a diagnosis. In England, only about one in ten intensive care babies referred from the screen turns out to have permanent hearing loss [6]. Most referrals resolve. The repeat testing exists precisely because the first test is unreliable in babies who have been unwell.

If hearing loss is confirmed, hearing aids, cochlear implants and early language support work, and they work better the earlier they start. Alongside that, expect your team to arrange developmental follow-up rather than only audiology. That is not a sign that something else is wrong. It is a recognition that things which appear later are found sooner when someone is looking — and earlier support consistently produces better outcomes, as In[Neo]Sight has covered in its article on a parent-delivered NICU intervention whose benefits widened through early school age.

It is also reasonable to ask your team directly: did my baby have jaundice needing an exchange transfusion, meningitis, cytomegalovirus, or a fungal infection? Those four in particular should trigger planned hearing follow-up, and knowing the answer helps you hold the system to it.

One more practical point is worth knowing. Hearing can change after the newborn period. Some children pass the first screen and develop hearing loss during the first two years, which is why babies with these risk factors are offered repeat testing rather than being discharged after a single normal result. If your child stops responding to sounds they used to notice, becomes harder to settle with your voice, or is slow to babble and then to use words, say so at the next appointment rather than waiting to be asked. Parents notice these changes long before a scheduled test does.

What researchers are working on next

The clearest opportunity is turning the unbound bilirubin measurement from a research tool into something a hospital laboratory can run routinely, so that jaundice treatment can be tailored to how vulnerable a particular baby actually is rather than to a single chart. Beyond that, both studies call for the same thing: research that reports hearing results separately instead of bundling them into a general "developmental outcome" score, that follows children for at least two years, and that offers genetic testing to everyone rather than only to children in whom a doctor already suspects a syndrome [6], [12]. Until then, the honest summary is the one both papers reach — hearing loss after intensive care is usually a marker of how ill a baby was, and a reason to watch a child's whole development with care rather than a problem confined to the ears.

References

  1. Wroblewska-Seniuk KE, Dabrowski P, Szyfter W, Mazela J. Universal newborn hearing screening: methods and results, obstacles, and benefits. Pediatric Research. 2017;81(3):415–422. doi:10.1038/pr.2016.250 ↩
  2. Colella-Santos MF, Hein TAD, de Souza GL, do Amaral MIR, Casali RL. Newborn hearing screening and early diagnostic in the NICU. BioMed Research International. 2014;2014:845308. doi:10.1155/2014/845308 ↩
  3. Joint Committee on Infant Hearing. Year 2019 position statement: principles and guidelines for early hearing detection and intervention programs. Journal of Early Hearing Detection and Intervention. 2019;4(2):1–44. doi:10.15142/fptk-b748 ↩
  4. Chant K, Bitner-Glindzicz M, Marlow N. Cumulative risk factors contributing to hearing loss in preterm infants. Archives of Disease in Childhood — Fetal and Neonatal Edition. 2023;108(5):464–470. doi:10.1136/archdischild-2022-324331 ↩
  5. Moosan H, Hoare DJ, Jayasinghe D, Willis KR, Martin K, Thornton SK. Neonatal markers of prematurity as predictors of permanent childhood hearing loss and neurodevelopmental impairment in children admitted to the neonatal intensive care unit. Brain Sciences. 2024;14(9):926. doi:10.3390/brainsci14090926 ↩
  6. Thornton SK, Patel R, Smith S, Ahmadinejad Farsangi S, Brough H, Pourhoseingholi MA, et al. Biological markers of hearing loss in neonates admitted to the neonatal intensive care unit: a systematic review and meta-analysis. Frontiers in Neuroscience. 2026;20:1796635. doi:10.3389/fnins.2026.1796635 ↩
  7. Kemper AR, Newman TB, Slaughter JL, Maisels MJ, Watchko JF, Downs SM, et al. Clinical practice guideline revision: management of hyperbilirubinemia in the newborn infant 35 or more weeks of gestation. Pediatrics. 2022;150(3):e2022058859. doi:10.1542/peds.2022-058859 ↩
  8. Amin SB, Saluja S, Saili A, Orlando M, Wang H, Laroia N, et al. Chronic auditory toxicity in late preterm and term infants with significant hyperbilirubinemia. Pediatrics. 2017;140(4):e20164009. doi:10.1542/peds.2016-4009 ↩
  9. Amin SB, Wang H, Laroia N, Orlando M. Unbound bilirubin and auditory neuropathy spectrum disorder in late preterm and term infants with severe jaundice. The Journal of Pediatrics. 2016;173:84–89. doi:10.1016/j.jpeds.2016.02.024 ↩
  10. Brumbaugh JE, Bell EF, Do BT, Greenberg RG, Stoll BJ, DeMauro SB, et al. Incidence of and neurodevelopmental outcomes after late-onset meningitis among children born extremely preterm. JAMA Network Open. 2022;5(12):e2245826. doi:10.1001/jamanetworkopen.2022.45826 ↩
  11. Fitzgerald MP, Reynolds A, Garvey CM, Norman G, King MD, Hayes BC. Hearing impairment and hypoxia ischaemic encephalopathy: incidence and associated factors. European Journal of Paediatric Neurology. 2019;23(1):81–86. doi:10.1016/j.ejpn.2018.10.002 ↩
  12. Thornton SK, Moosan H, Jayasinghe D, Willis KR, Martin K, Jayasinghe A, et al. Congenital anomalies identified during early childhood in NICU infants with bilateral hearing loss: a multi-centre longitudinal cohort study. Frontiers in Neuroscience. 2026;20:1836937. doi:10.3389/fnins.2026.1836937 ↩