Should you need urgent health advice please contact your GP or call NHS 111. In an emergency please visit A&E or call 999

We offer tailored content specific to your area. Check below to find your local area.

Choose your location for articles and services where your live:

Expressing breast milk – your questions answered

Expressing breast milk is a way of taking milk from the breast so you can store it to feed your baby at a later time.

It can be done for a number of reasons:

  • To increase your milk supply
  • To make your breasts more comfortable
  • To encourage baby to latch onto the breast
  • For your partner to be able to feed your baby
  • You are returning to work
  • If you’re separated from your baby, for example if they are born prematurely

Some of the most common questions mums ask about expressing breast milk are:

Q: When is it okay to express?

If you would like to express your breast milk, it’s advised to wait until breast feeding is established, usually around 4-6 weeks after the birth of your baby, to avoid an oversupply of milk and issues caused due to blocked ducts.

However, you may be advised to express earlier than this to help build up your available supply.

For example, a baby who for various reasons can’t sufficiently stimulate your supply, and may have slow weight gain. Expressing breast milk can boost the supply available through extra stimulation (expressing/pumping) and make feeding much easier.

Q: When is the best time of the day to express?

One of the best times to express breast milk is about an hour after an early morning feed as your breasts naturally have a fuller supply earlier in the day.

If you’re expressing to build up your breast milk supply, you can express in between each feeding session. Try to express an hour after a breast feed to ensure your breasts are well drained. Your breasts make more milk to replace any milk that has been removed.

If you’re expressing to replace a breast feed that is being missed, it’s a good idea to express when your baby would usually breast feed, usually every three hours.

If your baby only takes milk from one breast during a feed, you can express from the other one.

Q: How much milk should I express for a feed?

When you’re breastfeeding, it’s difficult to know exactly how much milk your baby is having at each feed, which makes it difficult to know how much you need to express.

Each baby is different and requires different amounts of milk at each feed. It’s advised to express your breast milk until your breast feels empty. You can then build up a stock of expressed milk so that this can be used when required.

Q: How should I store breast milk?

Breast milk’s antibacterial properties help it to stay fresh, so it can be stored at room temperature for up to 6 hours and in the fridge for up to eight days (stored at the back of the fridge, not the door of the fridge).

It can also be frozen in the freezer compartment of a fridge for up to two weeks, and for up to six months in a freezer that is -18°C.

It’s a good idea to label each sterilised bottle or container of breast milk with the date on which it was expressed, and the date it needs to be used by.

Q: How do I give my baby the expressed milk?

It is best to defrost frozen breast milk slowly in the fridge before giving it to your baby.

If you need to use it straightaway, you can defrost the milk by standing the bottle, bag or container it’s stored in in a jug of warm water, or by running the bottle under the warm tap. Never use a microwave to defrost or heat it.

Breast milk can be fed to your baby straight from the fridge, at room temperature or be warmed. Before you give the milk to your baby, check the temperature by shaking a few drops onto your wrist.

Breast milk can be given via a bottle or feeding cup.

Q: How can I encourage my baby to feed expressed breast milk from a bottle?

It’s important to make sure you’ve got breastfeeding well established before trying bottles to make sure it doesn’t affect your baby’s willingness and ability to breastfeed.

In the early days, if you are concerned that giving a bottle might cause ‘teat’ confusion then you can give your milk via a cup or syringe. You can discuss this with your health visitor for more advice and guidance.

If your baby is reluctant to take a bottle, try these tips:

  • Hold and cuddle your baby first
  • Warm and soften the teat by putting it in boiling water, ensuring it has cooled sufficiently down before using
  • Ask someone else to give the bottle – if it’s you, your baby may want to feed from the breast
  • Offer the bottle when your baby isn’t particularly hungry, but is alert and relaxed
  • Try using a different position to feed
  • If the baby is older (for example around four months old) try giving the milk to them in a cup
  • Some babies prefer one brand of bottle over another, so you may need to try an alternative

Q: Can I express and always feed breast milk by bottle?

Yes. If you are expressing and offering your breast milk by bottle, it’s recommended that you express three hourly during the day and at least once over night to establish your supply.

Useful links

National breastfeeding helpline

Page last reviewed: 22-03-2021

Next review due: 22-03-2024