Feeding your preterm baby on NICU

Parenteral Nutrition and IV fluids

When your baby is first born they might not be ready to start feeding orally (via their mouth). This is particularly true of lower gestation babies or babies who might not be able to feed enterally (to their tummy), e.g. awaiting surgery or are unwell, or when it’s expected that building up to full enteral feeds will take a long time.

In those circumstances we will start babies born <31 weeks (sometimes >31 weeks) on parenteral nutrition (nutrition through the vein) to support their growth until they’re able to introduce enteral nutrition through a nasogastric (via the nose) or orogastric (via the mouth) tube that helps to deliver milk straight into their tummies. The volumes of parenteral nutrition and enteral nutrition will be increased gradually and in line with your baby’s size and gestation.

Once the baby is able to have majority of their feeds orally or via a tube the parenteral nutrition can be weaned down and stopped.

Sometimes parenteral nutrition might be restarted if baby develops a problem with their gut and enteral feeds need to be stopped for a longer period of time.

Babies born >31 weeks and those expected to build up enteral feeds quickly might not start on parenteral nutrition, but receive IV fluids (usually glucose solution) until they build up their enteral (and/or oral) feeds.

Enteral nutrition

Your baby should be able to start having milk within the first 24 hours of birth, this can be via the breast or bottle if baby is mature enough to start sucking and swallow safely. However, in most cases, premature babies it will start having milk via a nasogastric (NG) or orogastric (OG) tube. Tube feeding allows baby to mature until it develops skills to take milk by mouth.

Expressed breastmilk (EBM) and donor expressed breastmilk (DBM/DEBM)

Offering maternal breastmilk is by far the most ideal way to start an enteral feeding journey – especially freshly expressed or warmed refrigerated breastmilk will offer the most benefits to your baby. It is easy to digest and provides immune support to help your baby fight infections, it is tailor-made to your baby.

It is particularly important for your baby to receive the first breastmilk – called colostrum. It is rich in nutrients and immunological properties, it is the best first milk your baby can have. All babies no matter how small (unless they have specific anatomical challenges) should be able to have tiny amounts of colostrum given on the inside of their cheek.

Expressing milk for your baby

When maternal milk is not available and baby was born at less than 32 weeks and/or 1.5kg we recommend offering donor milk rather than formula. It is a second best thing that can be offered to vulnerable infants. Although it doesn’t have the same immune support properties as fresh EBM (due to the processing it goes through) it will still be easier for the baby to digest and reduce baby’s risk of developing serious gut infections, when compared to formula.

You can read more about donor milk and milk banks

Breastmilk fortifier (BMF)

Maternal milk is the best choice for your baby. However preterm infant have very high requirements for calories, protein and certain nutrients, e.g. sodium, phosphate, calcium, vitamin A, vitamin D, etc. that cannot be met on breastmilk alone. As a result babies that are born <34 weeks and or <2kg would likely benefit from supplementing breastmilk with breastmilk fortifier. It is most commonly a powder than can be added to breastmilk to increase the amount of calories, protein and certain nutrients it provides.

It can help support baby’s growth, protein intake (important for brain and lung growth) and optimise intake of nutrients that help in reducing the risk of metabolic bone disease of prematurity, like vitamin D, phosphate and calcium.

Most units will start with half strength fortifier (that is a sachet in twice the amount of milk) and will progress to introducing full strength (usually a sachet in 25ml of milk) if it is well tolerated.

Some babies can initially struggle with tolerating fortifier and can have vomiting, bloating, diarrhoea or constipation – we can help reduce the risk of that happening by introducing it more gradually and once baby has been tolerating good volumes of EBM (usually over 100ml/kg/d). If baby’s discomfort persists, we might discontinue or halve the strength of the fortifier.

Further reading on BMF

Formula

When breastmilk is not available and baby does not meet criteria for donor milk, they might start their enteral feeds with formula. Formula can also be used alongside EBM if there isn’t enough EBM. There are different types of formula we use on the unit:

• Higher energy preterm formula (80kcal per 100ml) that tends to be used with lower gestation or smaller babies. It’s most similar in composition to fully fortified EBM. Most suited to babies born <1.8kg and/or <34 weeks. It cannot be prescribed outside of the hospital. Commonly used examples include Nutriprem 1® or SMA Goldprem 1®.
• Commonly referred to as “discharge formula”, is a step between higher energy preterm formula and term formula. It is a little higher in calories (72kcal per 100ml) than term formula. It can be introduced when baby is growing well or tracking up their centiles for weight and getting ready to go home. Most suited to babies born <2kg and <36+6 weeks. Commonly used examples include Nutriprem 2® (or SMA Goldprem 2®)
• Standard/term formula – First baby formula you can buy in a supermarket or over the counter. Provides 68kcal per 100ml. Most suited to babies born >2kg and >34 weeks. It can be introduced instead of “preterm discharge formula” to preterm babies once they’re growing well or tracking up their centiles for weight.

Babies born < 34 weeks will need to start on additional vitamins and iron (most commonly Abidec® and Sytron®) when having standard formula. These would normally continue until at least 6 months corrected age but can be offered until 12 months corrected age, especially if baby struggles with introducing a wide variety of foods in their diet.

You can find more information on baby milk, including safe preparation and safe bottle feeding on the First Steps Nutrition website.

Oral feeding

Your baby might be ready to start oral feeds, e.g. breastfeeding or bottles, when it starts showing hunger cues and wake around feed times. These can be individual to your baby, but most might start off by being more awake during feed time, rooting and opening their mouth, putting hands to mouth (see the picture below). Crying is usually a late cue that they’re hungry – if they do get to this stage it might be worth comforting them first and then offering a feed.

Some babies might start their oral feeding journey with non-nutritive sucking, this might include offering an expressed breast or a dummy or a gloved finger – this can help babies develop the skill of sucking, without having to swallow milk as they might not be developmentally ready to do so yet or their respiratory support might prevent safe swallowing/feeding.

Colostrum “Liquid Gold”

This is where colostrum (first milk you express) can come in very useful. It is concentrated milk – it contains lots of nutrition in very small amounts.

Read more about colostrum

Buccal (on the side of the cheek) colostrum can be given to almost all babies (not matter how preterm) the only exception would be babies who might have a structural defect in their GI tract, e.g. oesophageal atresia.

Establishing breastfeeding

There are many benefits to breastfeeding your baby but it can take some time to establish with a preterm baby so try not to get discouraged if this is your preferred way of feeding. You can use the “Expressing breastmilk on Neonatal unit” tool to help you keep keep a record of your expressing volumes.

It is not unusual to use formula or DBM alongside EBM or breastfeeding. This is common if there is insufficient maternal milk supply or if parents wish to stop expressing. You can offer your milk +/- formula in a bottle/NG feed.

However if your intention is to breastfeed your baby we would recommend that you aim to establish this first for a minimum of 1-3 weeks before you consider introducing bottles. This is because the mechanics of feeding from the breast and bottle are very different and experience tells us that babies that start having bottles before or when establishing breastfeeding can struggle to do so effectively. As a result they might take longer to establish breastfeeding and might delay going home.

Avoiding bottle use might mean that your baby might require top up tube feeds when they’re establishing breastfeeding to support their nutrition, until they’re able to take sufficient volume to support growth. We would also advise that you express your milk after breastfeeds whilst your baby learns to take more milk, which will support establishing a good supply for when your baby is ready to take more.

This can be difficult to coordinate sometimes therefore it’s advised that you have support from your midwife, health visitor, and most importantly a partner or family/friends for those first few weeks when you establish supply.

However, long term, you might find that breastfeeding requires less effort than feeding expressed milk or preparing formula.

If you’re concerned that your baby is struggling with establishing breastfeeding ask to speak to an Infant feeding specialist nurse, Speech and Language therapist and/or dietitian.

Growth

Babies grow very fast in the 3rd trimester of pregnancy. When they are born early the way they get their nutrients changes. They no longer rely on their umbilical cord to deliver nutrients to their bloodstream, but rather have to process milk and/or parenteral nutrition themselves. A lot of the time they might also be battling respiratory insufficiency, potential infections and temperature regulation – all of this (and more) requires extra energy.

It is normal for babies to lose a little weight when they’re first born. Partly because they can be born with a bit of excess fluid, and partly because that ready supply of nutrients has been cut off and babies need to learn to process nutrition by themselves without overloading their organs with too much fluid.

Babies should regain birthweight and start tracking a centile line in the first 2 weeks of life. Babies are weighed regularly on the neonatal unit and their weight is plotted on a growth chart. Those plots are then compared against a line of expected growth pattern (AKA a centile line). You can learn more about growth charts.

What if babies are deviating away from their centile line?

• If the pattern of growth trends down and keeps crossing centile lines downward that would be an indication of poor growth and an indication that something needs to change to support this baby’s nutrition.
• If the pattern of growth follows a centile line it would mostly likely indicate good growth. However it is useful to interpret this with a view of how much weight was lost from birth and whether it correlates with the head circumference and length centiles.
• If the pattern of growth crosses centiles in the upward direction the pattern of growth might be optimal (this might be true if baby is catching up following weight loss) or it could be excessive (especially if crossing above birth centile) – this might be an indication that the nutrition they’re receiving is too much for their needs and perhaps ready to step down to a more appropriate feeding plan for them.
• Fast weight gain is not ideal – this is because baby might be gaining fat tissue as opposed to laying down functional tissue like muscle, bone or brain.
• Slow weight gain may impact brain and lung development, as well as stunt overall growth.

Poor nutrition can also impact developing brain, lungs and bone health, which is why it is so important to try to optimise nutrition early.

Make sure to ask your neonatal team to show you your baby’s growth chart so that you can see for yourself.

Lots of things can affect growth. The most obvious is getting enough calories and protein from their milk or parenteral nutrition. However there are some less obvious reasons why baby’s growth might be slow, e.g. restricted intake, low tissue sodium or zinc, underlying conditions like hypothyroidism or treatment for certain conditions like steroids. It might be worth considering these if your baby is still struggling to grow on what would seem an optimal milk regimen – your neonatal team can discuss this with you.

Babies after abdominal surgery

Some babies have to have surgery to repair or remove damaged part of the gut. Depending on the amount of gut that was removed, their ability to absorb nutrients from their feed might be affected. Therefore, babies that have had surgery on their gut are at an even higher risk of poor growth and nutrition. They are more likely to have low sodium (especially if they had high losses through a stoma) and more likely to need larger feed volumes and/or specialist formula to support nutrition, ideally alongside maternal breast milk*.

*Maternal breastmilk is still the best choice for any baby, whether soon after surgery or later down the line, it will help them heal. However, due to their increased requirements they might need some support from formula or breastmilk fortifier – your neonatal team will be able to advise around this.

Going home

This can be an extremely exciting time that you might have been waiting for since your baby was born, but it can come with mixed emotions.

Growth can also be up and down around that time due to various changes, e.g. stopping breastmilk fortifier and introducing more breastfeeds, changing formula, reducing or stopping respiratory support, coming out of hot cot, starting responsive feeding etc. This can be normal. Some babies might need a little support to optimise their nutrition and some do not.

Sometimes babies might require small amounts of high energy formula, such as Infatrini® or SMA High Energy® (100kcal per 100ml) for a few weeks until they establish optimal volumes of breastmilk or formula.

Some babies might need to use a feeding tube to support their nutrition for longer than their stay on the unit and might go home with a feeding tube. If this is the case we will teach you how to use the tube and ensure that your baby is known to the Home Enteral Feeding team. They will be in charge of organising your baby’s tube feeding related equipment and milk (if needed).

It is important to continue to review your baby’s growth when home – your health visitor might be able to come out and weight your baby at home or you can go to your local health visiting Hub to have baby weighed.

You might want to start with weekly weights for the first 2-4 weeks and if growth is satisfactory (see “growth” section above) you might want to reduce it to every 1-3 months.

You can ask your neonatal team to give you a growth chart and show you how to plot your baby – you can also print them from the RCPCH website.