Milk During Cooling: What New Research Tells Parents About Feeding Babies Treated for Brain Injury at Birth

How two 2026 studies, one from hospitals in Rome and Brussels and one from a children's hospital in Chongqing, China, looked at whether and when cooled babies can safely be fed

Babies who are cooled to protect their brain after a difficult birth can usually be given small amounts of milk during the three days of cooling without extra harm to their gut, according to two studies published in 2026. Babies who were fed early tended to reach full milk feeds sooner, but they were also the more stable babies, so the milk itself may not explain all of the difference.

Why feeding a cooled baby became a question

Some babies go without enough oxygen and blood flow around the time of birth. This can injure the brain, a condition doctors call hypoxic–ischaemic encephalopathy, or HIE ("hypoxic" means short of oxygen, "ischaemic" means short of blood flow, and "encephalopathy" means the brain is not working normally). HIE is the most common cause of this kind of newborn brain problem, and it can lead to serious disability [1]. The main treatment is called therapeutic hypothermia, or simply "cooling": the baby lies on a special mattress or wrap that keeps the body a few degrees cooler than normal for three days, which gives the brain a better chance to recover. A large review of 11 research studies involving 1,505 babies showed that cooling reduces the chance of death or serious disability, and doctors now recommend it for babies with moderate or severe HIE who are identified within six hours of birth [2].

While a baby is being cooled, there is an everyday question that matters a lot to parents: can the baby have milk? Milk can be given through a thin tube into the stomach or, for some babies, by mouth. If milk is not given, the baby receives nutrition through a drip into a vein, which is called parenteral nutrition.

How doctors used to handle feeding during cooling

When cooling was first tested in large studies, doctors were cautious. One of the best-known studies was the TOBY trial, which tested cooling the whole body to 33.5 °C for 72 hours in 325 babies and was led from Imperial College London [3]. According to the Italian and Belgian research team whose study is described below, babies in TOBY were not given milk during cooling [4]. The worry was that a gut that had also been short of oxygen might not cope with milk, and might develop necrotising enterocolitis, or NEC, a serious inflammation of the bowel.

Over time, hospitals began to do things differently. A survey of neonatal units in the United Kingdom in 2017 found that 29 of 49 units (59%) gave some milk during cooling, usually in tiny amounts, but fewer than one in three had written guidance for staff [5]. A very large study of 6,030 cooled babies in England, Scotland and Wales found that about 31 in every 100 were fed during cooling, and that the most serious form of NEC affected just 7 babies in total [6]. A 2023 analysis that brought together six studies and 3,693 babies found serious NEC in fewer than 1 in 100 babies and no sign that feeding increased it, but concluded there was not enough evidence to say when to start or how fast to increase feeds [7]. Two small studies in which babies were allocated to early or later feeding by chance, one at a children's hospital in Chongqing, China, and one at a hospital in Istanbul, Türkiye, also found early feeding to be workable [8][9]. Even so, hospitals still do it differently, which is why the two new studies are useful.

What the Italian and Belgian study found

The first study, by Dr De Rose and colleagues, looked back through the records of 276 babies who were cooled between 2011 and 2024 at two large hospitals: Bambino Gesù Children's Hospital in Rome, Italy, and Cliniques Universitaires Saint-Luc in Brussels, Belgium [4]. The babies came from a group of 302 originally studied to see how often cooled babies need antibiotics [10]. Because the researchers wanted to look at feeding all the way to going home, they included only babies who survived and had complete feeding records.

In these two hospitals, 166 of the 276 babies (about 6 in 10) were given some milk during cooling. The amounts were very small in the first three days and then increased gradually. Tummy problems, which doctors call "feeding intolerance" and which include swelling of the belly, vomiting or milk left in the stomach, happened in 47 babies (about 17 in 100). NEC happened in only 3 of the 276 babies (about 1 in 100). All three had a milder stage of NEC, none needed an operation, and NEC was not linked to whether a baby had been fed during cooling [4]. Two of the three were among the 24 babies with the most severe brain injury.

Babies fed during cooling reached full milk feeds sooner (a typical 8 days compared with 12), went home sooner (11 days compared with 15) and were more often breastfed or receiving breast milk when they went home (about 80 in 100 compared with about 55 in 100) [4]. The researchers were careful to say that this does not prove the milk caused these benefits, because doctors had generally chosen to feed the babies who were more stable.

What the Chinese study found, and why it asked a different question

The second study, by Dr Yue and colleagues, was published earlier in 2026 and took place at the Children's Hospital of Chongqing Medical University in China, which looks after babies transferred from other hospitals [11]. It included 94 babies with moderate or severe HIE cooled between March 2024 and March 2025. Forty-eight started milk during cooling or the slow warming afterwards ("early"), and 46 started after warming was complete ("delayed"), following a hospital plan that began with very small amounts and increased them slowly.

This team was especially interested in a problem researchers call "confounding by indication". Put simply, when doctors decide which babies to feed, they naturally hold back milk from the sickest babies. If those babies later do less well, it can look as if not feeding caused the problem, when really they were sicker to begin with. The Chongqing study showed how big this effect is. Babies in the delayed group were much more likely to need a breathing machine (about 28 in 100 compared with 6 in 100) and medicines to support their heart and blood pressure (about 83 in 100 compared with 29 in 100) [11].

Tummy problems or NEC happened in about 22 to 23 in every 100 babies in both groups, and early feeding was still not linked to these problems after the researchers took the babies' illness into account. Early-fed babies came off drip nutrition about two days sooner and had lower hospital bills, but they did not go home significantly sooner [11]. In this hospital, no baby received breast milk at the very first feed, because the babies had been transferred from other hospitals and their mothers' milk was often not yet available.

What this means if your baby is being cooled

If your baby is being cooled, these studies offer reassurance. For babies who are stable, small amounts of milk during cooling appear safe, and serious bowel problems are uncommon. Tummy problems are fairly common, and the usual response is to pause or reduce feeds for a while, so a short break in feeding is not necessarily a sign that something has gone badly wrong. Other hospitals using careful feeding plans, for example in Calgary, Canada, and Cape Town, South Africa, also saw no cases of NEC [12][13].

If your baby is very unwell, for example needing a breathing machine or medicines for blood pressure, the team may wait before starting milk. That is a judgement about your baby's condition right now, not a missed chance. Both studies noticed that NEC, although rare, was more common among babies with the most severe brain injury. The numbers were very small, and the researchers say this is not a reason to stop feeding these babies, but it does mean their tummies may be watched especially closely when feeds begin.

Breast milk is the best first choice. If you are able to, expressing milk early, even while you are apart from your baby, is something the Italian and Belgian researchers encourage hospitals to support [4]. It is always reasonable to ask the team what their feeding plan is and how they will decide when to increase feeds.

What researchers are working on next

Neither study could prove that early feeding itself makes babies better, because babies were not put into groups by chance. Both research teams call for larger studies in which babies are allocated by chance to different feeding plans, so that sicker and healthier babies are spread evenly between groups. Researchers also want to know how fast feeds should be increased: an earlier study from the same Chongqing hospital found that starting earlier, with larger amounts or with faster increases, was linked to more tummy problems [14]. Future studies are likely to look separately at babies with moderate and severe brain injury, and at how best to help mothers provide breast milk during cooling.

The bottom line for families

For most stable babies being cooled after a difficult birth, small milk feeds appear safe, and serious bowel inflammation is rare. Babies who are fed early often come off drip feeding sooner, but part of that is because they were well enough to be fed. Your baby's team will balance these things for your baby, and breast milk, whenever possible, remains the best start.

References

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  2. Jacobs SE, Berg M, Hunt R, Tarnow-Mordi WO, Inder TE, Davis PG. Cooling for newborns with hypoxic ischaemic encephalopathy. Cochrane Database Syst Rev. 2013;2013(1):CD003311. doi:10.1002/14651858.CD003311.pub3 ↩
  3. Azzopardi DV, Strohm B, Edwards AD, et al. Moderate hypothermia to treat perinatal asphyxial encephalopathy. N Engl J Med. 2009;361(14):1349-1358. doi:10.1056/NEJMoa0900854 ↩
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  9. Arman D, Cömert S, Kara N, Gül A, Erol KE. The effects of nutrition on mesenteric oxygenation among neonates with neonatal encephalopathy: a randomized clinical trial. Pediatr Res. 2025;97(7):2390-2397. doi:10.1038/s41390-024-03648-9 ↩
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