Keeping the Tiniest Babies Warm at Birth: Does Drying Before Wrapping Help?

What a 2026 Italian study of 354 very premature babies (Cavallin et al., JAMA Network Open) found about warmth in the delivery room

Very premature babies lose body heat quickly, so delivery-room teams wrap them in plastic to keep them warm. An Italian study of 354 very premature babies tested whether drying a baby with a warm towel first helps more babies reach the neonatal intensive care unit (NICU) at a healthy temperature. It did not: about 46 in 100 were at a healthy temperature either way, so the study does not support adding drying as a routine step.

Why a baby's temperature matters so much in the first minutes

A baby who is born very early has a lot of skin for such a small body, very thin skin, and almost no fat to act as a blanket. Babies also cannot yet make much heat of their own. Add to that the fact that a newborn is wet from the womb, and you can see why the delivery room, which feels comfortable to adults, can feel like a cold day at the swimming pool to a tiny baby. Water evaporating from wet skin carries heat away, which is why you shiver when you climb out of a pool even on a warm afternoon.

This is not just a comfort issue. Over many years, researchers have noticed that babies who arrive in the NICU with a low body temperature tend to have more complications and a higher chance of dying, a link found in large groups of babies in the United States [1], Canada [2], Brazil [3] and several European regions [4]. Later work in the United States again linked colder arrival temperatures to poorer outcomes in babies born moderately and extremely early [5], and another large study described how common low temperatures were and what made them more likely [6]. These studies only show a link. A baby who is cold may also be a baby who is sicker for other reasons. Even so, keeping babies at a normal temperature, roughly 36.5 to 37.5 degrees Celsius, became an important goal for every unit caring for premature babies.

How the plastic bag became part of routine care

For a long time, the answer to a cold baby was to dry them off quickly and wrap them in warm towels. Then, in the late 1990s, a team of researchers tried something different: they tested placing very small babies in a plastic wrap at delivery instead [7]. The idea was that plastic keeps heat and moisture close to the skin, like a small greenhouse. Plastic wraps then became a common sight in delivery rooms. Later, a large review that gathered the evidence on ways to prevent chilling at birth looked at wraps alongside hats, warmed mattresses and other measures [8], and international experts who write guidance on newborn resuscitation include plastic wrap for premature babies in their recommendations [9].

That left a practical puzzle. If wet skin loses heat, drying the baby before wrapping seems like an obvious extra help. On the other hand, once a baby is inside a plastic wrap, the space inside becomes humid, and the wetness may matter much less. Drying also means a few more seconds of handling in a moment when the team is doing many other things. The question called for a large, fair comparison, which is what the study described next set out to provide.

The study: what researchers did and where

The NEODRY trial (drying before plastic wrapping in very preterm infants) took place in 21 specialist (tertiary care) hospitals in Italy, between February 2023 and July 2024 [10]. A "trial" here means a study in which babies were assigned to one approach or another by chance, like a coin toss, so that the two groups are as similar as possible and any difference between them is more likely to be due to the approach itself. The trial included 354 babies born in these hospitals who weighed less than about 1,500 grams (roughly 3 pounds 5 ounces) and/or were born at 30 weeks and 6 days of pregnancy or earlier. Babies with major birth defects were not included, and parents gave their consent.

Half of the babies (177) were dried with a warmed towel before being put in a plastic bag or wrap, and half (177) were wrapped without being dried. Everything else was the same for both groups: a room kept between 23 and 25 degrees Celsius, a heated bed with a warmer above the baby, a cap on the head, and, for babies who were doing well, a plan to wait a little before clamping the umbilical cord (in practice this happened for only about one baby in three). Some babies also had a warmed mattress or warmed, moist air for breathing support. The main thing the researchers measured was how many babies had a temperature between 36.5 and 37.5 degrees Celsius when they were admitted to the NICU. Because the teams could tell which approach they were using, the study could not be hidden from them, which is one of its limits.

What the researchers found about temperature

Drying did not help. In the group dried before wrapping, 46 in 100 babies (81 of 177) arrived in the healthy range; in the group wrapped without drying, it was also about 46 in 100 (82 of 177). The average temperatures were nearly the same, 36.4 and 36.5 degrees Celsius. The number of babies who were too cold or too warm did not differ enough to draw any firm conclusion. About half of the dried babies (50 in 100) and just under half of the undried babies (46 in 100) arrived colder than the healthy range, and a small number in each group were a little too warm.

Other common problems of very early birth, including bleeding in the brain, serious infections and lasting lung disease, were about as common in both groups. This means the researchers found no sign that drying protected babies in other ways either [10].

The finding about deaths, explained carefully

There was one result that families will understandably want to look at closely. More babies died before going home in the group dried before wrapping: 26 out of 177, or about 15 in 100, compared with 10 out of 177, or about 6 in 100, in the other group. The difference was seen mostly among the very youngest babies, those born before 28 weeks.

The research team looked carefully at the medical records of the babies who died. They found that most of the deaths could be expected because these were extremely premature or very ill babies, and none of the deaths were unexpected. They could not find any way in which drying, or the plastic wrap, would have caused a death. Their conclusion was that the difference may simply be down to chance. Chance can play a bigger role than people expect when the babies in a study are so fragile and the number of deaths is fairly small. This does not mean the question is closed, and the researchers did not claim it was; it means that, from what is known, the researchers could not find a reason to think drying harms babies, and there is also no evidence that it helps.

What this means for families and their baby's care

If your baby is born very early, the study does not mean the team did something wrong by drying or by not drying. What it shows is that this one step does not appear to make the difference we might have hoped for. The team will most likely keep using the whole set of measures that together keep babies warm: a warm room, the plastic wrap, a cap, a heated bed and, sometimes, a warmed mattress and warmed, moist air. You can read more about how these pieces fit together in our article on the neonatal hypothermia bundle, and about a related step in our article on delayed cord clamping.

The most important message may be that about half of all the babies in this study, whichever approach they got, arrived at the NICU a little colder than ideal. That does not mean those babies were harmed; it means keeping tiny babies warm is hard, even in well-equipped hospitals, and that teams continue to work on it. The study's hospitals differed from many others in a few ways, such as high rates of caesarean birth and less use of warmed mattresses and warmed breathing air, so the results may not apply in exactly the same way everywhere. The babies were also not followed after leaving hospital.

Questions you might ask the team include how they keep your baby warm in the first hour, what your baby's temperature was when they arrived on the unit, and whether anything is being done differently for a baby who is especially small.

What researchers are working on next

Questions that researchers could tackle next include what actually goes on beneath the plastic wrap, such as how much heat and moisture escape with and without drying. Another is testing the different warming steps together to learn which combinations work best, and following babies over longer periods. Because of the difference in deaths, other studies can also show whether the same pattern appears again or was a chance finding.

Conclusion: a step that did not help, and a challenge that remains

In this study of 354 very premature babies in 21 Italian hospitals, drying a baby before wrapping in plastic did not increase the number arriving at the NICU with a healthy temperature. The researchers did not think the extra deaths in the dried group were caused by drying, but they cannot rule out that possibility, so it needs to be checked in future studies. What families can take from this is that teams are actively working to keep the smallest babies warm, and that the whole set of warming measures matters more than any single step.

References

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  2. Lyu Y, Shah PS, Ye XY, Warre R, Piedboeuf B, Deshpandey A, et al. Association between admission temperature and mortality and major morbidity in preterm infants born at fewer than 33 weeks' gestation. JAMA Pediatr. 2015;169(4):e150277. doi:10.1001/jamapediatrics.2015.0277 ↩
  3. de Almeida MFB, Guinsburg R, Sancho GA, Rosa IRM, Lamy ZC, Martinez FE, et al. Hypothermia and early neonatal mortality in preterm infants. J Pediatr. 2014;164(2):271-275.e1. doi:10.1016/j.jpeds.2013.09.049 ↩
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  6. Miller SS, Lee HC, Gould JB. Hypothermia in very low birth weight infants: distribution, risk factors and outcomes. J Perinatol. 2011;31(Suppl 1):S49-S56. doi:10.1038/jp.2010.177 ↩
  7. Vohra S, Frent G, Campbell V, Abbott M, Whyte R. Effect of polyethylene occlusive skin wrapping on heat loss in very low birth weight infants at delivery: a randomized trial. J Pediatr. 1999;134(5):547-551. doi:10.1016/S0022-3476(99)70238-670238-6) ↩
  8. McCall EM, Alderdice F, Halliday HL, Vohra S, Johnston L. Interventions to prevent hypothermia at birth in preterm and/or low birth weight infants. Cochrane Database Syst Rev. 2018;2(2):CD004210. doi:10.1002/14651858.CD004210.pub5 ↩
  9. Wyckoff MH, Wyllie J, Aziz K, de Almeida MF, Fabres J, Fawke J, et al. Neonatal life support: 2020 International Consensus on Cardiopulmonary Resuscitation and Emergency Cardiovascular Care Science With Treatment Recommendations. Circulation. 2020;142(16 Suppl 1):S185-S221. doi:10.1161/CIR.0000000000000895 ↩
  10. Cavallin F, Doglioni N, Risso FM, Monari CB, Aversa S, Troiani S, et al. Drying Very Preterm Infants Before Plastic Wrapping at Birth: A Randomized Clinical Trial. JAMA Netw Open. 2026;9(3):e2556902. doi:10.1001/jamanetworkopen.2025.56902 ↩