Breastfeeding – expressing milk

Key points about breastfeeding and expressing milk

  • Expressing milk means you can provide your baby with breast milk when you are separated from them or when breastfeeding is not possible.
  • There are a number of reasons why you might want to or need to express milk rather than feed your baby directly from the breast.
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There are a number of reasons why as a breastfeeding mother you might want to express milk rather than feeding your baby directly from the breast:

  • Your baby may be premature and too small to suck properly. In this case, your expressed milk can be fed to the baby through a tube.
  • Some babies with a cleft lip or palate find it difficult to suck and need to be fed expressed milk with a specially shaped spoon or teat.
  • You may wish to leave your baby with someone else. Your expressed milk can be fed to your baby via a bottle, a cup, an eyedropper or a spoon.
  • If you are working outside the home and wish to provide breast milk for your baby when you are at work.
  • Breast milk contains antibodies which will help protect your baby against illness – which can be especially valuable if the baby attends a day care centre with other children and needs to be fed when you are not there.
  • You may simply wish to express a small amount of milk to mix with your baby's first solid foods.

There are several ways you can express milk:

Expressing by hand

Expressing milk by hand needs a fair bit of practice and is time consuming. You may need to enlist the help of your midwife, a friend or La Leche League. There are slightly different methods, but the main aim is to assist the 'let down' of milk and drain the milk sinuses. To stimulate the 'let down' you have to:

  • Start at the top of each breast and with each hand press inwards, moving your fingers in a circular motion on one spot for a few seconds.
  • Work around both breasts doing this.
  • Working around the breast again, stroke gently with a tickle-like stroking action, towards the areola (the dark area around the nipple).
  • To drain the milk sinuses, put your thumb about 2cm above your nipple and your first two fingers about 2cm below your nipple.
  • Gently roll your thumb and fingers around in a slight twisting action by pushing inwards.
  • Do not press too hard.
  • Work all around the areola repeating this action.
  • Keep expressing like this until the milk flow slows down and do the same on the other breast after about three to five minutes.
  • Repeat on both breasts.
  • The milk comes out in small bursts at first and then flows freely.

Expressing using a pump

Whether you use an electric or a hand vacuum pump you still have to stimulate the 'let down' as you would for expressing by hand. If using a pump be careful not to exert too much suction on the nipple. Pumps can occasionally be a bit fierce and crack or split the nipple. A pump should be treated like a baby's feeding bottle and needs to be sterilised thoroughly after use.

It is best to express directly into a sterilised airtight plastic container with a lid, or a sealable bag.

Storage times

  • Bench: If you don't have access to a fridge, breastmilk can be kept on the bench for up to 4 hours as long as the temperature is less than 24ºC and it is stored in a covered container.
  • Fridge: The milk can be kept in the fridge for up to 72 hours (3 days) at <4ºC. Store at the back of the fridge where it is cooler and not in the door.
  • Freezer options: Breastmilk can be frozen for:
    • up to 2 weeks in a freezer box inside a fridge
    • 3–6 months in a freezer compartment of a fridge/freezer
    • 6–12 months in a separate chest freezer (deep freeze). 

Label each container with the date, month and year and use the oldest milk first. Also write ‘Expressed Milk’ on the container in case someone mistakes it for something else. Do not add fresh, warm expressed milk to milk which is already frozen or cold.

Frozen milk is best thawed by holding the container under cold running water then gradually warmer water to bring the milk to body temperature. Breast milk is not homogenised (milk, fats etc all mixed together) so it will separate. Swirl gently to mix. Microwaves are not recommended for thawing breastmilk as they heat unevenly and your baby's mouth or throat could get burned. Don't leave expressed milk standing around for long at room temperature. It's not safe to refreeze milk either, so throw away any leftover milk.

You can phone Plunketline on 0800 933 922(external link)(external link) anytime day or night for advice about breastfeeding.

You can also talk to your midwife, doctor or Plunket nurse. For detailed help, contact a lactation consultant(external link)(external link).

Other groups to contact include La Leche League(external link)(external link), and your local Parents Centre(external link)(external link).

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