Infant and toddler health

Breast milk storage: Tips for storing breast milk

Breast milk storage can be confusing. Follow these tips to make the most of your expressed breast milk.

If you're breast-feeding your baby and going back to work or looking for more flexibility, you're probably considering using a breast pump. Once you start pumping, it's important to know how to safely and properly store your expressed breast milk. Consider these do's and don'ts for breast milk storage.

What kind of container should I use to store expressed breast milk?

Store expressed breast milk in capped glass or plastic containers that have been cleaned in a dishwasher or washed in hot, soapy water and thoroughly rinsed. Consider boiling containers after washing them if the quality of your water supply is questionable.

If you plan to store breast milk for three days or less, you can also use a plastic bag designed for milk collection and storage. While economical, plastic bags aren't recommended for long-term breast milk storage because they may spill, leak and become contaminated more easily than hard-sided containers. Also, certain components of breast milk may adhere to the soft plastic bags during long-term breast milk storage, which could deprive your baby of essential nutrients. If you use breast milk storage bags, place them in containers for greater protection in the refrigerator and freezer.

What's the best way to store expressed breast milk?

You can store expressed breast milk in the refrigerator or freezer.

Always wash your hands before handling expressed breast milk. Using waterproof labels and ink, label each container with the date and time of your earliest contribution. If you're storing expressed breast milk at your baby's child care facility, include your baby's name on the label. Place the containers in the back of the refrigerator or freezer, where the temperature is the coolest.

To minimize waste, fill individual containers with the amount of milk your baby will need for one feeding. You might start with 2 to 4 ounces (59 to 118 milliliters), and then adjust as needed. Also consider storing smaller portions — 1 to 2 ounces (30 to 59 milliliters) — for unexpected situations or delays in regular feedings. Keep in mind that breast milk expands as it freezes, so don't fill containers to the brim.

Can I add freshly expressed breast milk to already stored milk?

You can add freshly expressed breast milk to refrigerated or frozen milk you expressed earlier in the same day. However, be sure to cool the freshly expressed breast milk in the refrigerator or a cooler with ice packs for at least one hour before adding it to previously chilled milk. Don't add warm breast milk to frozen breast milk because it will cause the frozen milk to partially thaw. Keep milk expressed on different days in separate containers.

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References

Riordan J, et al. Breastfeeding and Human Lactation. 4th ed. Sudbury, Mass.: Jones and Bartlett Publishers; 2010:561.
Mannel R, et al. Core Curriculum for Lactation Consultant Practice. 2nd ed. Sudbury, Mass.: Jones and Bartlett Publishers; 2008:521.
The Academy of Breastfeeding Medicine. Protocol #8: Human milk storage information for home use for healthy full-term infants. New Rochelle, N.Y.: Academy of Breastfeeding Medicine; 2004:1.
Martinez-Costa C, et al. Effects of refrigeration on the bactericidal activity of human milk: A preliminary study. Journal of Pediatric Gastroenterology and Nutrition. 2007;45:275.
Hoecker JL (expert opinion). Mayo Clinic, Rochester, Minn. Sept. 10, 2009.
LaFleur EA (expert opinion). Mayo Clinic, Rochester, Minn. Sept. 17, 2009.

MY00926 Dec. 1, 2009

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Infant and toddler health