Expressing for premature babies

How do I express for my premature baby?

If a baby is premature and has breastfeeding challenges, mothers need to start expressing early to establish and maintain their milk supply. Ideally, they start within one hour of birth using manual expression and pumping with a double electric pump. Once the milk comes in, mothers can usually just continue expressing with a double electric pump and stop manual expression. Mothers should express every 3 hours and aim for at least 7 sessions in 24 hours. Once the baby is starting to breastfeed, they should express after the baby has breastfed and ensure there are least 7 expressing sessions each day. Mothers should try to express as much milk as possible, even if the baby is not using it all. Emptying the breast ensures there will be enough milk as the baby grows and prevents the supply from decreasing. Expression is stopped once the baby is breastfeeding well and the milk supply is maximized.

A) Expressing when the baby is premature

Many premature babies cannot breastfeed effectively. Instead, their mothers need to express to establish, increase, and maintain their milk supply to provide breast milk and its attendant benefits for these babies. Expressing early also protects mothers from breast engorgement.

Many mothers focus more on breastfeeding and less on expressing. However, keeping a sleepy baby at the breast when breastfeeding is not effective may calm the baby but also take time that may be better spent expressing. 

The priority is to feed the baby and maintain the milk supply until the baby can breastfeed effectively. If a mother has limited time for one session of feeding, supplementing, and expressing, it may be best to skip the breastfeeding rather than the supplementing or expressing.

B) Equipment for pumping, collecting, and storing

Compared with full-term babies, very premature babies do not have strong immune systems. It is very important to follow guidelines for cleaning pump parts and storing breast milk.

Mothers expressing colostrum while in hospital may choose to collect it in small sterile needle-free syringes. Colostrum is only present in small amounts and may be wasted when collected in regular containers. Syringes can be used to collect colostrum, store it, and then deliver it right to the baby.  

Some hospitals provide syringes, pumps and pump parts, containers for storing breast milk, and other feeding tools.

Please discuss these topics with your health-care providers as recommendations can vary between babies and institutions. 

C) Establishing the milk supply

To establish a milk supply, it is extremely important to start breast stimulation within one hour of birth. Ideally, this is by effective breastfeeding, but this is often a challenge for premature babies. Instead, early, frequent and regular expressing right after birth can prevent the milk from coming in late and ensure a good milk supply whereas delays in expressing can reduce breastfeeding success.

Within one hour after delivery, mothers should express with a combination of manual expression for ten minutes on each breast and machine pumping, also for ten minutes on each breast. A double and electric pump is the most effective type of pump in this situation. Mothers should do this every three hours and aim for at least 7 sessions in 24 hours. This can be done after the baby breastfeeds or instead of breastfeeding, depending on the baby’s abilities.

It has been shown that when pumping, mothers of premature babies may produce more milk if the pumping rhythm is similar to that of a baby’s sucking (Meier 2012). This requires a high quality electric pump; these are often available for use by mothers of hospitalized babies.

D) Expressing after the milk comes in

Once the milk comes in and until the baby can breastfeed effectively, mothers only need one effective expression method. Pumping with a double electric pump is generally more effective than manual expression when the baby is premature. 

1) Express regularly and often

Mothers should continue to express every 3 hours and aim for at least 7 sessions in 24 hours. Some mothers feel better if they sleep longer at night. We recommend they have only one 5-hour sleep at night and move the day pumping sessions closer together so they are still pumping 7 times in 24 hours.

Once the baby is learning to breastfeed, mothers should express after the baby has been at the breast. They should still ensure they are expressing at least seven times a day.

2) Empty the breast at each expression

A mother should aim to express as much milk as she can even if the baby is not yet taking in all the milk the mother is making. Emptying the breast at each session ensures there will be enough milk as the baby grows and prevents the milk supply from decreasing.

Extra milk is frozen and stored. It is never wasted! If appropriate, it can also be donated to a milk bank.

Hands-on pumping, which combines breast compression with machine pumping, can also help increase and then maintain the milk supply.

3) Other ways to help maintain the milk supply

Mother should keep their babies in skin-to-skin care as much as possible (Hake-Brooks 2008).

Having the baby in regular contact with the mother’s breast and nipple can help maintain the milk supply. Depending on their maturity and health, babies may:

  • Nuzzle.
  • Lick.
  • Use non-nutritive sucking.
  • Breastfeed.

4) Monitor the expressed amounts of milk

Mothers should keep track of how often they pump and how much milk they get at each session. Choices for this include paper, a spreadsheet, or an app. There are several free apps available online.

Mothers should express the expected amounts of milk and the amounts should not decrease.

The amount of milk produced after two weeks can indicate how much milk a mother is likely to continue to produce. Mothers who produce about 500 millilitres (17 U.S. fluid ounces) each day by two weeks are likely to be able to feed their babies exclusively with breast milk (Hoban 2018). This amount should continue to increase to about 800 ml (27 oz) within one month.

E) Address low or decreasing expressed amounts

While it can be frustrating to not produce enough milk to meet all of the baby's needs, any breast milk given to a baby has benefits.  

1) Low expressed amounts

A few mothers are never able to make enough milk. There are a number of possible causes including having a premature birth.

Other mothers may have their milk come in late.

2) Decreasing amounts of expressed milk

Babies will start taking more milk from the breast as:

  • They develop their breastfeeding skills.
  • They grow and need larger amounts of milk.  

At the same time, it is normal for expressed amounts to slowly and steadily decrease.

However decreasing expressed amounts can also signal a problem.

3) Solutions

If mothers are not expressing the expected amounts of milk at each session, they should consider changing their techniques, review the possible causes and solutions, and talk with their health-care providers.

Some mothers of premature babies use medication such as domperidone to increase their milk supply. Research on its effectiveness in this situation has shown limited improvement in production. It has shown small increases in breastfeeding rates in premature babies at the time of discharge from hospital (Grzeskowiak 2018).

F) When to stop expressing

1) When to continue expressing

a) To support the milk supply as the baby learns to breastfeed

Once premature babies start breastfeeding occasionally or regularly, it is still important to express after each breastfeeding session. Premature babies may leave milk behind in the breast which can result in a decreasing milk supply. This happens because these babies:

  • Are still not strong enough to remove all the milk they need from the breast.
  • Are small and do not need all the milk in the breast.

By expressing after the baby breastfeeds, there will be enough milk for any supplements that are needed and enough milk for the growing baby. 

As babies get better at breastfeeding and continue to grow, the expressed amounts slowly decrease. 

b) To maintain the milk supply if the baby has not learned to breastfeed

Some mothers need to express for the long-term as their babies do not learn to breastfeed. 

2) When it is safe to stop expressing

a) When the mother has a full milk supply

When mothers have a full milk supply, they need to continue expressing after breastfeeding until the baby:

  • Breastfeeds effectively.
  • No longer requires supplements to grow well.
  • Is either:
    • At 42 weeks after conception and weighs at least 3,000 gm (6 lb 9 oz).
    • At 44 weeks after conception.

If mothers have a large milk supply and are expressing a lot of milk after the baby breastfeeds, they may have to gradually decrease the amount they express as breast fullness allows. Suddenly stopping expressing can result in:

b) When the mother has a low milk supply

When mothers have a low milk supply, they need to continue expressing after breastfeeding until: 

  • The baby can latch, suck, and breastfeed well.
  • Expressed amounts are consistently less than 15 ml (1/2 oz) from each breast and:
    • The baby is otherwise well.
    • The expressed amounts of milk are only a small part of the baby's total milk intake.
    • The baby is unlikely to benefit from the small amounts of expressed breast milk.
    • Further expressing is unlikely to increase milk production.

3) After expression is stopped

  1. If the baby is growing well without supplements, the baby's growth should simply be monitored routinely.
  2. If the baby always needs supplements with other milk after breastfeeding, the mother may have a permanently low milk supply. These babies will need ongoing supplements. Again, the baby's growth should be monitored.


Grzeskowiak LE, Amir LH, Smithers LG. Longer-term breastfeeding outcomes associated with domperidone use for lactation differs according to maternal weight. Eur J Clin Pharmacol. 2018 May 3
Hake-Brooks SJ,  Anderson GC. Kangaroo care and breastfeeding of mother-preterm infant dyads 0-18 months: a randomized, controlled trial. Neonatal Netw. 2008;27(3):151–159
Hoban R, Bigger H, Schoeny M, et al. Milk Volume at 2 Weeks Predicts Mother's Own Milk Feeding at Neonatal Intensive Care Unit Discharge for Very Low Birthweight Infants. Breastfeed Med. 2018 Mar;13(2):135-141

Meier PP, Engstrom JL, Janes JE, et al. Breast pump suction patterns that mimic the human infant during breastfeeding: greater milk output in less time spent pumping for breast pump-dependent mothers with premature infants. J Perinatol. 2012 Feb;32(2):160