The complete resource for NICU families from admission to discharge and beyond

You don’t understand what has happened! Your baby was due in about a month – or maybe even less – and everything was supposed to be fine. You know lots of women who have delivered their babies a couple weeks early, and they went to the normal nursery. But your baby is in the NICU and can’t be with you. A couple of weeks doesn’t make any difference, does it?

Babies born between 35 and 38 weeks are called late preterm infants, and can be some of the most frustrating and unpredictable patients in the NICU. Your new son or daughter looks like a term baby, and probably weighs about the same as a term baby. You heard him/her cry in the delivery room, and may even have gotten to hold him/her for a brief time. Your baby may have even gone to the normal newborn nursery initially, but then someone told you your baby was being admitted to the NICU. You are confused and frightened and need information!


Humans need surfactant in their lungs to breathe normally, and the ability for the lung to make surfactant occurs at about 34 – 35 weeks EGA or later. The inside of the newborn lung is wet (after all, it was just filled with fluid a short time ago) and the wet air sacs (called alveoli) stick together, making it hard to fill with air. Have you ever tried to blow up a balloon that has had water inside it before trying to fill it with air? Or tried to separate two glasses in the dishwater that were stuck together? A chemical reaction called surface tension between the water molecules on the two surfaces is responsible for this, and surfactant (a soapy substance) breaks this surface tension.

Late preterm babies may be lacking adequate surfactant to help them breathe normally, and this is can be seen in a baby who is struggling to breathe. Babies born by c-section (especially without any labor) are more likely to have trouble, because they were entirely unprepared for birth! (Labor lets the baby know that big things are about to happen!) For reasons we don’t understand, boy babies – especially caucasian – seem to have the most difficulty. Grunting and retractions are the terms used to describe the symptoms of respiratory distress your baby may be experiencing.

Nasal CPAP

To treat his/her breathing troubles, your baby may be placed on a breathing machine, with a tube placed in his/her windpipe. Surfactant that is obtained from either cows or pigs may then be instilled into your baby’s lungs through this tube. (This advance won the Nobel prize in medicine in 1997.) The breathing tube probably will not stay in long and your baby may have a device placed in his/her nose that is blowing air into the lungs to keep them inflated. This is called Nasal CPAP (Continuous Positive Airway Pressure). When breathing normally, air is sucked in through the nose or mouth by the vacuum created inside the chest when the diaphragm drops. If the chest wall is weak – like in a preterm baby – or if too much pressure is needed to inflate the air sacs – like in surfactant deficiency – rather than pulling in air, the chest wall collapses. Think of trying to suck a really thick milkshake through a straw – the straw will collapse before you get any milkshake! Rather than having to suck in the air to inflate the lung, CPAP blows air into the lung, like blowing up a balloon. Once the air sacs are open, it’s easier for your baby to breathe.


Whether your baby needs extra oxygen may be a separate issue from whether s/he has difficulty breathing. The air that we breathe contains 21% oxygen, and 79% other stuff – mostly nitrogen. Your baby may have his/her level of oxygen saturation measured continuously while in the NICU, via a light on his hand or foot called a pulse oximeter. If the number reading on the monitor is lower than desired, your baby will be given extra oxygen – all the way up to 100% oxygen and nothing else. Although oxygen is essential for life – just like water – too much of a good thing can be a bad thing, and too much oxygen can be harmful. For this reason, pulse oximeter readings are watched closely and the level of oxygen adjusted.

Your late preterm baby may need to be on some respiratory support for a few days or more, but almost certainly will be breathing independently before discharge. The problems s/he may have had in the days/weeks after birth, once resolved, will not return and will have no long lasting impact.


Late preterm babies frequently have difficulties feeding, either at breast or from a bottle, and this may have prompted the NICU admission. Feeding difficulties is one of the most frustrating problems seen in the NICU! Your baby looks like s/he should be able to feed, and perhaps was feeding okay in the first few hours or days after birth. S/he has a vigorous suck and is making those cute litte “baby faces” like s/he wants to eat, but just won’t. The harder you try, the worse it gets and now there’s a feeding tube going into his/her nose or mouth that ends in the stomach. You think the nurses just aren’t trying hard enough, and you are angry.

Feeding is one of the most complicated tasks asked of a newborn baby. To successfully feed, an infant must not only suck, but must also swallow the liquid that is in the mouth and – oh yes – breathe at once/second and not choke. This is called suck/swallow/breathe coordination and is a brain development skill that appears around 37 – 38 weeks EGA. (As with everything, some babies develop it earlier, but this cannot be predicted.) It is not developed by practice, and prolonged efforts to bottle or breastfeed your baby before s/he is ready will only tire him/her out. A baby capable of feeding will ingest a full feed (either at breast or from a bottle) in about 10 minutes, and efforts longer than 20 minutes are generally considered counterproductive. Other than time, there is no treatment to accelerate feeding readiness.

Temperature control

Your baby may be in an incubator or under a radiant warmer. These are devices that provide heat to your baby so that s/he does not have to burn calories to stay warm. Remember that we are warm-blooded, which means that we need to keep our body temperatures between a very narrow range, and we burn calories to do this. Maintaining temperature is so vital to our survival that we will burn every source of calories available – not just fat but also muscle and lean tissue. During gestation, most of a baby’s fat is stored in the last few weeks of pregnancy and a baby born prematurely may not have adequate fat stores to help with temperature regulation. An outside heat source, like an incubator or radiant warmer, provides that extra heat so that your baby’s calories can go to other things, like feeding and breathing, and gaining weight. Because your baby will do everything s/he can to keep his/her temperature normal (and you can’t see how many calories it’s taking to do this), s/he will have a “normal” temperature on the thermometer regardless of whether it’s warm enough in the room for him/her.

Discharge readiness

It may seem like your baby is ready to go home NOW and the NICU is not providing any care you can’t do at home. This is not true. Every NICU care provider wants to get your baby home to you as soon as it is safe to do so – and not one minute longer! To be ready to go home, any baby (with small exception) needs to be doing four things:

  1. Breathing – your baby must be breathing independently, on room air, requiring no extra support and never forgetting to breathe. If your baby has had episodes of apnea, bradycardia, or desaturation, none must have occurred within the past several days that required some sort of intervention from a care giver.
  2. Feeding – Your baby must be taking all his/her feeds at breast or from a bottle, and not needed any tube feeds for at least 24 hours or more prior to discharge. (Occasionally, infants are discharged home w/feeding tubes in place, but this is unusual. Speak to your neonatologist if you have questions about this.)
  3. Temperature – Your baby must be maintaining a normal body temperature in a regular baby crib or bassinette, dressed in normal baby clothes. As it may take a while for adjustment, hopefully your baby will have been out in a crib for several days before discharge.
  4. Gaining weight – The ultimate test of discharge readiness is doing all of the above three things, and gaining weight. Steady and adequate weight gain is essential for a baby to thrive. All of the above tasks take energy to accomplish, and, after all is said and done, your baby must do all those things and still have enough energy left over to gain weight. You can plot weight gain on a specialized preterm baby growth chart if desired, available for download in the “My NICU” section of this site.