Hi mamas, I’m Stephanie Weight Hadfield, an International Board Certified Lactation Consultant (IBCLC) and mom of 4. I’m here to talk about one of our most frequently asked question topics, breastmilk storage. Hope this answers your questions!
Fresh human milk is a dynamic, living substance. It is packed with live immune cells that actively target and kill bacteria, so it takes longer to spoil than pasteurized cow’s milk or formula. This is one of the many reasons why so many mothers choose to pump their breast milk when away from baby. Our Pumping and Storing Breastmilk online class has so many tips to make this easier on mom. In this post, I will discuss the necessary care when handling your precious milk. Learn these breastmilk storage guidelines to make sure your pumped milk maintains all of its wonderful nutritional and immune protecting properties. Here are some easy-to-remember tips:
Handling your pumped milk:
- Wash hands thoroughly with soap and running water for at least 20 seconds before expressing your milk. (sing the alphabet song in your head to get the timing right)
- Store milk in clean glass or plastic containers with tightly fitting lids or heavy duty plastic bags designed for breastmilk storage. Breastmilk storage bags are a space-saving option for freezing milk. Ordinary plastic storage bags are not recommended for breastmilk storage, because they can easily tear and leak. (1)
- Clearly label the milk with the date it was expressed, as well as your child’s name if it will be given to a childcare provider. Use the oldest milk in the fridge or freezer first.
- Wash bottles and pump parts in hot, soapy water after use. Pump parts and bottles can generally be washed on the top rack of a dishwasher too; check the manufacturer’s instructions on your specific items to be sure. Sterilizing bottles and pump parts is unnecessary for healthy, full-term babies. (2)
- Store milk in smaller portion sizes to minimize waste. Storing in 2-ounce amounts and offering additional amounts if the baby is still hungry will prevent having to throw away unfinished milk. Having a few 1 oz portions stored can also be helpful for times that baby is hungry but mama is on her way. (3)
Guidelines for storing your pumped milk:
The U.S. Centers for Disease Control and Prevention (CDC) offers ranges of time that milk can safely be left at for certain temperatures, you can find them here if you want to take a look. I like to recommend a simple rule that fits within these ranges and is easy to recall, even for the most sleep-deprived parents. Just remember 5-5-5.
- 5 hours at room temperature. If the room is very warm (more than 85 degrees F/29 degrees C), 3-4 hours seems to be a safer time range.
- 5 days in the fridge (store milk in the back of the refrigerator where the temperature is the coldest.)
- 5 months in a regular freezer (the separated compartment in a typical fridge/freezer unit) According to the CDC, milk frozen for longer than the recommended time ranges is safe, but may be lower in quality as some of the fats in the milk break down.
Other time ranges that don’t fit as neatly within the 5-5-5 rule, but are still helpful:
- Human milk can be stored for 6-12 months in a chest or upright deep freezer.
- Human milk can be safely stored with ice packs in insulated storage bags for up to 24 hours.
Milk Thawing and Use
Thawing slow and gently is the best way to preserve the immune properties that protect your baby and prevent milk contamination. An easy option is to thaw in the refrigerator overnight. You can also hold the container under warm running water or place in a bowl of warm water for a few minutes.
Never thaw or heat milk in the microwave. It can destroy many of the milk’s anti-infective factors. The uneven heating of microwaves can also cause hot spots that can burn your baby’s mouth or throat even if milk is swirled or shaken afterwards. (4)
Thawed milk can be refrigerated for up to 24 hours. The current guidelines for milk storage recommend that thawed milk should not be refrozen. However, in a 2006 study, researchers froze, thawed and then re-froze and re-thawed donor milk and tested batches that were then refrigerated or left at room temperature. None of the batches developed unacceptable bacterial counts or decreased vitamin content compared to a control batch that was only frozen once. (5) This indicates that current recommendations might be more conservative than necessary, and you may want to consider this as you make decisions about using your expressed breastmilk.
Have you taken Lactation Link’s Pumping and Storing Breastmilk video course? It’s packed with helpful information and will answer many questions about pumping and milk storage that you didn’t even know to ask.
Thanks for stopping by,
Stephanie Weight Hadfield, BS, IBCLC
(1) Garza C, Johnson CA, Harrist R, et al. Effects of methods of collection and storage on nutrients in human milk. Early Human Development 1982;6:295–303
(2) Pittard WB 3rd, Geddes KM, Brown S, et al. Bacterial contamination of human milk: Container type and method of expression. American Journal of Perinatology 1991;81:25–27
(3) Academy of Breastfeeding Medicine. (2010) Clinical Protocol Number #8: Human Milk Storage Information for Home Use for Healthy Full Term Infants [PDF-125k]. Princeton Junction, New Jersey: Academy of Breastfeeding Medicine.
(4) Quan, R., Yang, C., Rubenstein, S., Lewiston, N.J., Sunshine, P., Stevenson, D.K., et al. (1992). Effects of microwave radiation on anti-infective factors in human milk. Pediatrics, 89(4 Pt 1), 667-669.
(5) Rechtman, D. J., Lee, M. L., & Berg, H. (2006) Effect of environmental conditions on unpasteurized donor human milk. Breastfeeding Medicine, 1(1), 24-26.