Expressing breastmilk and different kinds of breast pumps

What is expressing?

Expressing milk means taking milk out of the breast by hand or using a pump. The milk can then be stored and given to the baby from a bottle or other method. This might be a feeding cup, tube, syringe or supplemental nursing system (NHS, nd).

The baby can be fed with the milk straight after it is expressed. Or it can be stored in the fridge or freezer and given at a later date (NHS, nd).

Expressing milk and which pump to use is a personal choice and the experience will be different for different people. Talking it over with a breastfeeding counsellor or peer supporter can be useful to help decide what works for the individual. 

Why might I express?  

The breastfeeding mother or parent might want to express so that (Breastfeeding Network, 2019; NHS, 2023):  

• Colostrum (the first milk that is produced) is stored before birth, and can used if the baby needs extra milk in the first few days.
• Supply is stimulated.
• A baby that is born prematurely or is ill can be fed with breastmilk.
• Breastmilk can be given to the baby when the breastfeeding mother or parent is not there, for example while at work or going out for several hours without the baby. 
• The father or co-parent can give the baby milk. This is one of the ways to share caring responsibilities and one-on-one time with the baby.
• The baby can still receive breastmilk even if the mother or breastfeeding parent does not want to feed directly from the breast. 

Expressing breastmilk can take time and patience. The decision to express breastmilk is a personal one and should be made by the mother or breastfeeding parent. There shouldn’t be pressure to express so that someone else can feed the baby (La Leche League, 2025). 

Preparing for all types of expressing (NHS, nd; NHS, 2023):

It can take a little while for the milk to start flowing. It might help to cuddle the baby, visualise them, or smell their clothes (NHS, 2023).

• Wash hands with warm water and soap. 
• Have a sterilised container close at hand to collect the milk in. 
• Heat or warmth can help the milk to flow more easily. The breastfeeding mother or parent might like to express after a warm bath (if they are expressing at home). Or they might like to express after covering breasts with a warm towel first. 
• If expressing in a public place (eg a hospital), ideally choose a quiet, comfortable area. 
• Get comfortable and where possible, choose a time when there’s no pressure or rush.  
• It may help to cover or look away from the container to reduce the pressure of ‘how much’ has been expressed. 
• There may be a certain time of day when it feels easier to express more milk. 

Guide to hand expressing

Expressing breastmilk by hand can take a little practice, but knowing how to hand express can be useful to (La Leche Leage, 2025; NHS, 2023, UNICEF):

• Express a few drops of milk from the breast to help the baby attach and feed in the early days (Breastfeeding Network, 2019).
• Remove a little milk to relieve engorgement in the early days or as patterns of feeding change.
• Provide expressed milk without using a pump.
• Remove a small amount of milk to mix with solid foods.

How to hand express (NHS, 2023):

• Form a ‘C’ shape with the forefinger and thumb of one hand. 
• Place the 'C shaped' finger and thumb 2-3 cm back from base of the nipple and squeeze gently.  
• Try not to slide the finger along the skin. 
• Take care not to squeeze the nipple itself. 
• Hold and then release, then repeat. 
• The milk will appear as little beads on the tip of the nipple. 
• When the milk flow slows down, rotate the ‘C’ to a different spot and start again.  
• Once all the way around the breast has been worked on, move onto the other breast if possible. 
• It is worth experimenting with different positions and pressures to find out what works for the individual. 

This video from UNICEF provides a good demonstration of how to do this. 

Hand expressing colostrum

Colostrum can be expressed and stored from around 36 to 37 weeks of pregnancy (Breastfeeding Network, 2019). It usually comes out in tiny beads and can be sticky, so is tricky to collect. It can be helpful to try expressing twice a day for a short amount of time, maybe around 5-10 minutes (Breastfeeding Network, 2019).

A midwife can provide small 1 ml or 5ml syringes to catch the tiny droplets. The milk should be labelled with the date and frozen the same day in a clean container or resealable bag (The Breastfeeding Network, 2019).

How can supply be stimulated?

When the baby is born, aim to stimulate breasts at least 8, ideally 10-12 or more, times a day from breastfeeding or expressing to establish the milk supply (The Breastfeeding Network, 2019).

The baby needs to be fed at least 8, but ideally 10-12 or more times a day, so if expressing milk to store, this should be on top of feeds. This is why some breastfeeding parents decide to wait until feeding feels more settled and life has more rhythm.

Some mothers and breastfeeding parents express to store excess breastmilk above the baby’s needs. This can be useful, but can also maintain the oversupply which can lead to engorgement. 

Expressing using a breast pump

There are several different types of breast pump. Whichever pump is being used, clean and sterilise it before use and always refer to the manufacturer’s instructions.  

It is possible to express milk while feeding the baby on the other breast. This can produce more milk than pumping when not feeding, as the hormones are already working. It also saves time and means the mother or breastfeeding parent doesn’t need to express at another time. 

Silicone pump

This is a milk collector which attaches the breast with a silicone flange or rim by suction. It can be used to extract drops of milk released from the other breast while the baby is breastfeeding (La Leche League). However, using these too much in the early days might lead to oversupply of milk (La Leche League, 2025).  

Manual pump

Manual pumps use a lever which is squeezed by hand to pump milk out of the breast. They are convenient to use for occasional pumping. They can also be used for relieving milk from an uncomfortably full breast (La Leche League, 2025).  

As they don’t require electricity, they can be used anywhere and they don’t make a lot of noise. They are also less expensive than electric pumps (NHS, nd). However they require someone, normally the mother or breastfeeding parent, to pump them by hand.

Electric pump

Electric pumps, like manual pumps, copy the sucking motion of a baby (NHS, nd). They can be battery or mains operated. Battery operated pumps mean that the mother or breastfeeding parent is able to move around while using them.

Some find that they can get milk out of the breast more quickly than manual pumps, however they tend to be more expensive (NHS, nd). Start on the lowest setting then gradually build up to a higher setting as comfortable (NHS, nd).

Electric pumps can pump from one breast or both breasts (double pumps). Pumping from both breasts can save time.  

Wearable pumps can be fitted to one or both breasts and can be used whilst moving around or doing other tasks.

Open vs closed systems

• A closed system means that the pump has a membrane to stop milk droplets from getting into the pump.  
• Where a pump uses a closed system, this means it can be used by more than one person, and for any siblings born in the future. 
• Many electric pumps sold today use a closed system, but some don’t. 
• If buying a pre-owned pump, or if buying a pump with the intention to use it for more than one baby, it is important to check if it uses a closed system. 

Hospital grade pump

These are pumps suitable for use in hospitals. They are usually used (NHS, d):

• If the baby is exclusively fed with expressed milk 
• To increase milk production 
• When a baby is born prematurely or is spending time in special care. 

In a hospital, they are free to use, and are used several times a day and by different people (La Leche League, 2025; NHS, nd). Some hospitals and neonatal units offer the option to borrow a pump for use at home. It is also possible for parents to buy or hire hospital grade pumps themselves. 

Summary of breast pumps

How to express using a pump

Follow the tips above for hand expressing, but instead of using the hand to squeeze milk out of the breast (NHS, nd):

• Start by massaging the breast gently to stimulate the let-down reflex. 
• Put the breast shield or funnel over the nipple and start to pump on the lowest setting. 
• It may take a few minutes for the milk to start to flow. 
• Pump until the flow slows down, then pause or switch breasts.  
• Sometimes repositioning, adding a warm compress, or gentle massage can encourage the flow to start again. 
• When the flow from this breast slows, swap back to the first breast as flow may have increased. 
• Label the milk with the date and time and store in the fridge or freezer, unless it is being fed to the baby soon after. 
• Wash and sterilise the parts of the pump that have come into contact with the breast and milk. 

How long should I express for?

The time it takes to express will depend on the method of expression and individual parent. The time it takes to express may reduce once the mother or birthing person becomes more confident and used to expressing (NHS, nd). Colostrum is thicker and lower in volume so can take more time to collect.

Rather than expressing to a set time, it can be more effective to express until the flow of milk slows down to a slow drip. Some people find it helps to cover the holder rather than constantly watching the amount of milk filling it. This can lead to frustration if it doesn’t fill up as quickly as hoped, which may slow the rate of milk. 

How much and how often should I express?

How much and how often to express depends on what the expressed milk is needed for. If exclusively expressing, more milk will be needed than for occasional expressed feeds.

If expressing to build up a supply of stored breastmilk before returning to work, for example, milk could be expressed one or two times a day. This could be done after feeds. Expressed milk could also be taken from one breast while the baby feeds from the other (La Leche League, 2025).

Our Breastfeeding Counsellors are available every day of the year to talk about any questions or concerns about expressing. Call 0300 330 0700 between 8am and midnight. 

How to store expressed milk

Breastmilk has unique anti-bacterial properties. It will keep at a moderate room temperature after being expressed for up to four to six hours (less during summer months) (NHS, nd; The Breastfeeding Network, 2019). After this, the guidance is to throw it away. However, if there isn’t a plan to use it soon after being expressed, it’s best to store it in the fridge or freezer (NHS, nd).

Expressed milk can be kept in a sterilised container or a special pouch for expressed milk. It stays at the highest quality when kept in the fridge, as freezing can affect some of the nutrients and the anti-infective properties (The Breastfeeding Network, 2019). Defrosted frozen breast milk is still an excellent source of nutrition for the baby (Breastfeeding Network, 2019).

Write the date and name on the storage container before storing in the fridge or freezer (NHS, 2023). It can be kept (NHS, 2023):

• At the back of a fridge (not in the fridge door) for up to eight days, or three days if the temperature in the fridge is higher than 4°C or the temperature isn’t known. 
• In a cool box with ice packs for up to 24 hours. 
• In the freezer compartment of a fridge for two weeks.  
• In a freezer at -18°C or lower for up to six months.  
• If milk is being expressed in a hospital, talk to medical staff about how and where to store the milk.

Don’t use stored breastmilk that smells sour (particularly defrosted breastmilk) (Breastfeeding Network, 2019).

How do you defrost or warm milk?

Frozen milk can be defrosted gradually in the fridge or warmed in a bowl of warm water (to defrost it more quickly). If defrosting in warm water, it should be used immediately. Don’t use a microwave to warm up milk as it can lead to hot spots which burn the baby’s mouth.

What quantities should it be stored in?

Discard the milk if it is not finished within an hour of the baby starting to drink it. If more milk is expressed than the baby would normally have in one feed, separate it into different storage containers to avoid too much waste (NHS, 2023). Around 30ml of milk per container or pouch is a good starting point until it’s known how much the baby usually drinks (The Breastfeeding Network, 2019).