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How to safely store breastmilk

By The Health News Team | August 4, 2023
Bags of frozen breastmilk

If a baby can’t have its own mother’s milk, the American Academy of Pediatrics (AAP) recommends feeding the baby with another mother’s donated milk, when available. This, says Lisa Simpkins, a board-certified lactation consultant and certified perinatal educator affiliated with Sharp Mary Birch Hospital for Women & Newborns, is because human milk is designed to support human growth and brain development, while contributing to a baby’s immune system.

Breastmilk is especially vital for preterm babies. However, not all new mothers can breastfeed due to various medical or personal reasons, such as a low milk supply, inadequate infant weight gain or the challenges of pumping at work.

“Sharp Mary Birch Hospital for Women & Newborns is home to the largest level 3 neonatal intensive care unit in California,” Simpkins says. “We use over 30,000 ounces of donated breastmilk annually to support the health and growth of our tiniest patients.”

Additionally, feeding a baby with breastmilk and formula, also known as mixed feeding or combination feeding, can be the best solution for some families. Parents may choose to supplement breast milk with formula for a variety of reasons.

“While it is true that breast milk is ideal for your baby, breastfeeding does not need to be an or all-or-nothing process,” Simpkins says.

Answers to your top questions about safely storing breastmilk

However, if you do choose to exclusively breastfeed your baby, use donor breastmilk, go the combination feeding route, or exclusively hand-express or pump and bottle-feed your baby, it’s important to know how to safely store breastmilk. Simpkins shares answers to commonly asked questions about breastmilk storage and sharing.

Do I have to freeze breastmilk?

According to the AAP and the Centers for Disease Control and Prevention (CDC), freshly expressed or pumped milk can be stored at room temperature for up to 4 hours; in the refrigerator for up to 4 days; or in the freezer for up to 12 months. However, a maximum of 6 months in the freezer is recommended. Heat-pasteurized donated breastmilk needs to be consumed within 3 months. Hand hygiene is very important to remember before pumping or expressing and while preparing milk for storage.

Use containers expressly made for storing breastmilk and make sure they are tightly closed before storing them. Always note the date the milk was expressed or pumped, and store no more than 4 ounces in each container to avoid having to throw out unused milk.

What type of container should be used to store breastmilk?

Using glass containers, BPA-free plastic containers or bags, or the pitcher method are all considered good options for storing breastmilk. The pitcher method involves collecting milk from multiple pumping sessions in a 24-hour period in a single pitcher kept in the refrigerator. This can enhance the consistency of nutrients and save time. At end of the 24-hour period, the milk should be separated into storage containers, dated and placed in the freezer. Remember to stir the contents of the pitcher before separating the breastmilk into containers and freezing them.

Does the color of my breastmilk matter?

Color changes and separation of the creamy, fattier milk from the waterier properties of breastmilk is normal. You will see your milk go from clear; to yellow, thick colostrum; to transitional milk, which is yellow but has more volume; and then to the mature milk, which takes on a white milk appearance.

Milk color and flavor can also change based on the lactating parent’s diet. A varied diet contributes to less fussy eaters when the baby begins to eat solid foods because they have been exposed to different flavors during breastfeeding or breastmilk feeding.

What breastmilk shouldn’t be frozen?

Breastmilk is usually very stable when you follow storage guidelines. However, it’s important to remember:

  • Women taking some medications, including some HIV medications and drugs used to treat cancer, should not freeze or use their own breastmilk to feed a baby.

  • Milk pumped when drinking alcohol or using recreational drugs should not be given to a baby and should not be stored.

  • Milk pumped during a nipple thrush infection, also known as a yeast infection, may need to be discarded because the fungus is not killed in the freezing process. During infection, women should talk with their doctor about prompt treatment for both mother and baby, as it's a shared infection, and the use of stored milk after successful treatment.

How should I transport frozen breastmilk?

Transporting milk can be safely done in an insulated cooler or cooler bag with frozen cooler packs to keep milk cool before its use. Milk thawed in a refrigerator or cooler with frozen packs needs to be used within 24 hours. Refreezing milk isn’t recommended.

Is it OK to feed my baby breastmilk from my friends or family members?

Many people throughout the centuries have milk-shared. And when sharing with people you know and love, it’s easier to accept milk without putting it through the pasteurization process because you know the donors’ histories and lifestyles.

However, the AAP does not recommend informal milk sharing, especially if a donor if unknown, because of the increased risk of exposing infants to diseases, medications, alcohol, illegal substances or other contaminants. If you do choose to use informally donated milk, it’s important to ask the following questions:

  • Is the milk donor willing to share health or lifestyle information that could possibly impact the safety of their milk?

  • Does the donor use any substances, such as tobacco, alcohol, drugs, medications or supplements that could be present in the milk?

  • Is there a cost to buy or ship the milk?

  • What protocols are used to collect, store and transport the milk safely?

Breastmilk can also be purchased at area milk banks. Milk bank donors go through extensive evaluation and testing to ensure they are healthy before being allowed to donate milk. The milk is also tested and goes through a pasteurization process before being sold or donated.

Breastfeeding isn’t always easy, but having breastmilk as part of a baby’s diet is important for their health. If you are unable to breastfeed, talk with your baby’s doctor about the benefits of breastmilk and whether donated milk might be right for you and your infant.

Learn more about breastfeeding; get the latest health and wellness news, trends and patient stories from Sharp Health News; and subscribe to our weekly newsletter by clicking the "Sign up" link below.

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