Breastfeeding a Premature Baby

A baby born before 37 weeks of completed gestation is called premature or preterm. Premature babies (also called prems or preemies) may need to spend time in a special care baby unit or neonatal intensive care unit for help with breathing, temperature regulation, fluid loss, feeding and more. Many of the reflexes needed for breastfeeding such as extending the tongue to grasp the breast, the rooting reflex, or being able to coordinate sucking, swallowing and breathing may not be fully developed. All these difficulties can make breastfeeding a premature baby challenging, but breast milk is extremely important to these tiny babies and breastfeeding is possible from as early as 28 weeks gestation.

This article

This article answers some of the frequently asked questions about breastfeeding a premature baby and premature baby development. It is a companion article to Kangaroo Care for Your Premature Baby.

#1 How soon can my preemie breastfeed?

By 28 weeks gestation a baby will have a strong rooting reflex and be briefly able to latch on for a few sucks although this may not be very coordinated. By 31 weeks, a baby will manage repeated swallowing of milk from the breast. By 30-32 weeks, babies can coordinate the suck, swallow and breathe needed for breastfeeding and by 34 weeks a baby can fully breastfeed 1 2 3. By looking after your baby in kangaroo care (carrying your baby in skin-to-skin contact) he may learn to breastfeed sooner than these guidelines.

Even a 28 week prem can breathe properly on her mother’s chest, can breastfeed properly, and all her body systems can adapt to her new life.

Until your baby can breastfeed

  • Kangaroo mother care (KMC) alongside any medical help that is needed, is well recognised as the best care for a preterm baby. Kangaroo care helps your baby stabilise his heart rate and oxygen levels, prepares him for breastfeeding sooner and promotes healthy brain development. See Kangaroo Care for Your Premature Baby for further information.
  • You can hold your baby skin-to-skin as much as possible even while he receives medical support such as CPAP (continuous positive airways pressure), ventilation 4, treatment for jaundice or has intravenous fluids 5. Your baby can stabilise more quickly in skin-to-skin contact. Your health professionals will help you position your baby on your chest so that his tiny neck and airway are supported in the “sniffing position” to help him breathe.
  • Start hand expressing straight away within an hour of the birth if possible, your breast milk is very important for your baby. See #10 below for an idea of how often to pump and what volume of milk to aim for and read more about hand expressing, pumping and milk storage.
  • Alternatives to breastfeeding for the very premature baby are usually a progression from total parenteral nutrition (intravenous feeding, direct in a vein) to tube feeding by naso- or oro-gastric tube (NGT or OGT) to finger feeding to cup feeding and finally to full breastfeeding (Bergman, 2010). Bottles are not usually preferred see #6 below. Small premature babies lose fluids quickly, they may need intravenous fluids until a mother’s milk comes in and baby may still need expressed breast milk by cup or tube alongside breastfeeding for a while. During tube-feeding a baby can practice sucking the breast or mother’s finger. For a comparison of feeding methods see Optimal Feeding of Low-Birth-Weight Infants (WHO, 2006).
  • Seek help. A lactation consultant can help you find good positions for your tiny baby to breastfeed and support you to build a good supply of breast milk. Some premature babies may find feeding easier with a nipple shield. Practicing breastfeeding is important, even if initially your baby sucks without taking any milk. If your baby is not ready to coordinate sucking, swallowing and breathing at the same time, they can practice sucking skills on a pre-pumped (empty) breast.

premature baby breastfeeding

#2 Why is breast milk so important for a premature baby?

Breast milk is important for all babies but even more so for premature babies who are so underdeveloped. Breast milk takes over the work of the placenta to continue your baby’s development. Breast milk provides active enzymes to help baby digest the milk and help the intestines mature, antibodies and immune factors 6, anti-inflammatory factors, anti-oxidants, growth factors, and hormones. All these provide optimal brain growth, better bone density, protection from sickness, infections and childhood disease. Industrial formula can increase the risk of necrotising enterocolitis (NEC – a life threatening bowel condition in premature babies), allergies, asthma, Sudden Infant Death Syndrome, meningitis, heart disease in later life, and reduces survival rates 7.

Gestation specific milk

The breast milk produced at the particular time your baby is born is said to be adapted for that stage of your prem baby’s development. Compared to “full-term” breast milk, one study found premature baby milk had higher concentrations of protein, sodium, chloride, iron and magnesium in the first four weeks after birth 8. After the first weeks the raised levels fall but the protein in breast milk is easier to digest and babies energy expenditure is lower with breast milk compared to industrial formulas 9.

Preterm formula preparations

Enriched artificial milk developed specifically for the preterm baby is inferior to breastmilk and has poorer survival outcomes 10. For more reading see Supplementing With Formula and Human Milk Fortifiers.

formula milk is designed for a baby cow and only has about 30 nutrients; your breast milk will give her the 1200 nutrients that a human baby needs for her brain to grow properly.

#3 Is breast milk enough for a premature baby? Do prems need extra nutrients?

Opinions seem to vary on whether breast milk needs fortifying with certain nutrients for the very smallest premature babies. One study found breast milk was enough for very low birthweight babies in the weight group 1251-1500g 11. When needed, vitamin and mineral supplements (such as vitamin D, calcium, phosphorus and iron) can be provided either as individual nutrients, or via commercially-produced multi-nutrient fortifiers to be mixed with human milk. Multi-nutrient fortifiers are usually cows’ milk based, known as “human milk fortifiers”. See Human Milk Fortifiers for a discussion of the risks and benefits and the current recommendations from the World Health Organisation.

#4 How quickly do preemies grow?

The UK has separate growth charts available for babies born at 32 to 36 weeks’ gestation for boys and girls and a low birthweight chart for preterm baby boys and girls born before 32 weeks’ gestation 12

Growth rate

Preterm babies are said to have a slower weight gain than babies born at term. Expected growth rates cited in Kangaroo Mother Care, A Practical Guide, World Health Organisation, 2003 are:

􏰀 20g/day up to 32 weeks of post-menstrual age, corresponding approximately to 150-200g/week;
􏰀 25g/day from 33 to 36 weeks of post-menstrual age, corresponding approximately to 200-250g/week;
􏰀 30g/day from 37 to 40 weeks of post-menstrual age, corresponding approximately to 250-300g/week.

Gestational correction for preterm babies

Gestational correction is a way to adjust for gestational age if a baby is born before 37 weeks and is used until the baby is one year old or until two years of age if they were born before 32 weeks gestation 13. For more information about plotting preterm birth charts see UK-WHO Growth Charts – Fact Sheet 5 Plotting Preterm Infants.

#5 Can I improve my premature baby’s weight gain?

Improvements in a prem baby’s weight gain have been noted with:

Kangaroo care and skin-to-skin

All babies benefit from being held skin-to-skin. But for premature babies this appears to be even more important for their growth rate 1415 16 and healthy brain development. Jill and Nils Bergman have noted preterm babies who can grow at the same rate as a term baby when carried skin-to-skin in kangaroo care and several other studies have confirmed an increased weight gain and many other benefits. See Kangaroo Care for Your Premature Baby for more information.

mother holds premature baby skin-to-skin
© Olga Khoroshunova/

Raising fat levels in breast milk

If a baby isn’t gaining weight well on his mother’s milk, despite a mother having plenty of milk, it is possible to adjust the fat levels in breast milk and so raise the calorific value by knowing:

  • The fat content of milk increases towards the end of a feed. If you’re pumping, milk expressed towards the end of a pumping session will have a higher fat content. If baby is feeding directly at the breast, breast compressions can help release higher fat milk.
  • Breast milk tends to have higher calorie content in an evening 17
  • Breast milk can be centrifuged to obtain the higher fat cream layer at the top of the milk which can be used to increase the calorie concentration of breast milk. This can be done in a milk bank 18.

Fortifying human milk?

As discussed above, industry made cows’ milk based fortifiers are sometimes added to breast milk to promote faster weight gain in premature babies. Studies indicate fortifiers can create short term weight gain but there can be health concerns associated. For a full discussion see Human Milk Fortifiers.

Using donor breast milk

If you do not have enough breast milk see #9 below for ideas to increase your supply. In the mean time pasteurised donor breast milk from a milk bank is much better for your baby than preterm formula until you can build your milk supply.

#6 How often should my premature baby breastfeed?

In your uterus your baby would have been fed constantly via the placenta. Premature babies have very tiny stomachs and if a feed is too big it leaves them prone to reflux, higher risk of aspiration in their lungs, pneumonia, bradycardia, apnoea, colic, and NEC (Bergman, 2010). Small feeds more frequently are likely to be preferable 19, and more stabilising. In Hold Your Prem the authors suggest feeding preemies small volumes every 60-90 minutes.

#7 Is breastfeeding tiring for my baby?

Hospital staff may tell you that breastfeeding is tiring or stressful for your baby, however studies have found that breastfeeding as a general feeding method is less stressful than bottle feeding 2021 and cup feeding is less stressful than a bottle feed 22. In one study, there was no difference in preterm babies’ resting energy expenditure when they were breastfeeding compared with bottle feeding23. And another study indicated babies’ energy expenditure appeared to be less when they were breast milk fed compared with formula fed24. If a mother’s milk supply is very low however, or if a baby does not have enough stamina to finish a feed, they may fall asleep at the breast without having had much milk. This can be mistaken for breastfeeding seeming to be more tiring. Each baby will need to be assessed carefully to find the best combination of feeding methods for their needs until they are able to breastfeed effectively.

Falling asleep at the breast?

Falling asleep at the breast doesn’t necessarily mean that breastfeeding is tiring. Babies fall asleep at the breast after a good feed all the time. However, as mentioned in the paragraph above, the baby who falls asleep at the breast before he has finished his feed may do so because they are not getting a good flow of milk and because they don’t have much stamina. This can be common in premature babies and underweight babies. Improving the flow rate by improving the latch, using breast compressions or using a supplemental nursing system may help to keep baby awake for longer. Supplementary bottle feeds alongside breastfeeding may sometimes be the best option for a particular baby. An IBCLC lactation consultant can help you with your milk supply (see #10 below) and general breastfeeding management.

#8 Are pacifiers a good idea for my premature baby?

Generally pacifiers can interfere with breastfeeding by affecting latch and suck, affecting future teeth alignment, and are linked with causing ear infections. However for the premature baby they may be helpful if they prevent a premature baby from crying and so the stress and damage that can result from crying. Sucking a pacifier during tube feeding may also stimulate the vagus nerve to facilitate digestion (if the breast is not available) 25. For the baby in skin-to-skin, pacifiers are not generally needed.

#9 Why don’t I have much breast milk?

In addition to the potential reasons for No Breast Milk After Delivery or Reasons for Low Milk Supply the mother of a premature baby can have additional risks for low milk supply:

  • Routine administration of corticosteroids during uncomplicated premature labour may be a cause of lower milk supply 26
  • The effect of a stressful birth increasing stress hormones
  • Breast development may have not completed due to a shorter gestation or if the placenta was not functioning optimally.

#10 How can I increase my milk supply?

  • Start hand expressing in the first hour after birth and then hand express or pump at least every two hours during the day and once at night. A goal of hand expressing or pumping 750­­–1000ml (25­­–34oz) by 7­­–10 days after birth will help protect milk supply for the following weeks 27. If breastfeeding twins a mother will be aiming for double these volumes.
  • Have early skin-to-skin contact between mother and baby and practice kangaroo baby care.
  • Discuss galactagogues (foods, herbs and prescription medication that can help milk supply) with your doctors.
  • Encourage baby suckling on an empty breast if they are not mature enough to breastfeed yet 28.
  • See How to Make More Breast Milk and How to Increase Milk Supply While Pumping.
  • Contact an IBCLC lactation consultant for help with positioning and milk supply.


Breast milk is very important to a premature baby who may have complex medical needs. Skin-to-skin care can help with brain development, stability, weight gain and facilitate breastfeeding. Premature babies can begin to breastfeed at around 28 weeks gestation. There is a mix of opinions on the safety of bovine based breast milk fortifiers and whether the faster weight gain they claim to encourage is beneficial or outweighs the potential harm of introducing cows’ milk products. It is important to get good help to get your milk supply established and optimised.