Clinical Reference Systems: Pediatric Advisor 10.0
The Storage and Handling of Breast Milk
There may be times when you need to be away from your baby
and unable to nurse. You may need to return to work before
your baby has stopped nursing. The baby's father or another
relative may want to feed the baby. Or, your baby may not
be able to breast-feed for a while because of a medical
problem. In all these instances when your baby can't be
breast-fed, it is best for your baby to be fed milk that has
been pumped from your breasts. Thus, you will want to know
how to handle and store your breast milk safely for later
PREPARATION AND HYGIENE
- Always wash your hands thoroughly before you pump your
- A daily shower or bath will keep your breasts clean.
- After each use of a breast pump, wash all the parts that
come into contact with your milk. Use hot soapy water.
- Tell your doctor and your baby's doctor if you become ill
or need to take any medication.
COLLECTION OF MILK
- Pour the milk expressed during one pumping session into a
clean plastic container. (Plastic is better than glass
because some of the immune factors in breast milk stick
to glass.) You may use a plastic bottle that has been
washed in soapy water and rinsed, or a disposable bottle
bag. If you use disposable bottle bags, put one inside
another to prevent tears or holes.
- Tightly cap bottles. Do not store bottles with nipples
attached. Bottle bags are best closed with a clean
- Label each container with your baby's name and the date
and time the milk was expressed.
- Put several bottle bags in a larger plastic bag to
prevent them from sticking to the freezer shelf.
STORAGE OF BREAST MILK
Milk may be stored:
- In the refrigerator for up to 48 hours after pumping or
thawing (assuming the temperature of the refrigerator is
34 to 40 degrees F, or 1 to 4 degrees C)
- In a freezer inside a refrigerator for up to 3 weeks
after pumping (assuming the temperature of the freezer is
20 to 28 degrees F, or -7 to -2 degrees C)
- In a separate-door freezer for up to 3 months after
pumping (assuming the temperature of the freezer is 5 to
15 degrees F, or -15 to -9 degrees C)
- In a deep freezer for up to 6 months after pumping
(assuming the temperature of the freezer is 0 degrees F
or below, or -18 degrees C or below).
THAWING OF MILK
Milk may be thawed:
- Slowly in the refrigerator. Volumes of 3 or more ounces
(100 or more milliliters) of milk may take several hours
- Relatively quickly under running warm water. Place the
container of milk in a clean bowl or cup. Be sure the
top of the container remains above the water at all
WARMING OF MILK
You need only to take the chill off cold milk. You do not
need to heat it. You may warm chilled milk:
- under warm running water
- in a pan of warm water (not over direct heat)
- in a purchased bottle warmer.
ABOUT MICROWAVE HEATING
Authorities recommend AGAINST using a microwave oven to
either thaw or heat expressed milk. Milk can overheat very
easily in a microwave. Babies have been accidentally burned
by milk that was too hot. Furthermore, many of the immune
properties of breast milk can be destroyed by overheating.
- DO NOT thaw milk by letting it sit out of the refrigerator
or freezer at room temperature.
- DO NOT overheat milk. Overheating will cause it to
curdle and will destroy some immune components.
- DO NOT leave milk at room temperature for more than
- Milk may be reheated and used for the next feeding if it
has not been left at room temperature for more than
1 hour. Throw out any milk left after a second feeding.
- DO NOT refreeze thawed milk.
- DO NOT store milk in the door of your freezer, where the
temperature may change frequently.
- Always transport milk on ice in an insulated cooler.
- For healthy babies who are not in the hospital, it is
safe to layer milk collected at different times on the
same day in the same bottle. Chill freshly expressed
milk in the refrigerator before adding it to previously