One of the most frequently asked questions is: "How long does breast milk stay good for?"
The wonderful thing about breast milk is that it is alive! It has pre and probiotics that help coat your newborn's intestinal tract and keep it healthy. So the real question is, how do we store this breast milk to make sure it has the optum amount of nutrients for our newborn without any harmful bacterial growth.
We like to refer to the CDC, or Centers for Disease Control and Prevention, and ABM, or Academy of Breastfeeding Medicine, guidelines when passing out informaiton that has to do with health and wellness. These breast milk storage guidelines were last reviewed on June 11, 2021. It is important to frequently check guidelines because they may have changed over the years or between the time you have each child.
Storing fresh breast milk, no matter the storage location, make sure that your fresh milk is in a sterile, bpa free, container with an air tight lid. You may use storage bottles or storage bags. Freshly pumped breast milk can be left in a room temperature environment, with a sealed top, for up to 4 hours. Before the 4 hour mark is reached we recommend feeding this fresh milk to your baby, storing in the refrigerator or placing it in the freezer. Another important thing to remember is to label your stored milk with the date and time at which it was expressed.
To refrigerate your breastmilk you, again, want to choose an air tight container, label it with the date of expression and keep it at or below 40 degrees F (4 degrees C) for up to 4 days. A temperature higher than this can cause bacterial growth which can cause illness. Once you are ready to use this breastmilk you may serve it cold, room temperature or warm. NEVER microwave your breastmilk. This can cause hot spots in the liquid gold and burn the baby's mouth/throat. To warm safely, place bottle or milk storage bag in a bowl of warm water until the it has reached your desired temperature.
Frozen breast milk follows similar guidelines. Make sure to label the date, thaw and serve. You want to keep your breast milk in a freezer that reaches a 0 degrees F (-18 degrees C) for up to 6 months to 1 year. It is great to use a freezer that you may not open as frequently to meet optimal storage guidelines. Arranging your breastmilk with the newest in the back of the freezer seems like a no brainer. But who are we kidding?! We don't have much of a working brain right after having children.
Once you are ready to utilze this breast milk you may thaw it in the refrigerator and store for up to 24 hours after thawing is complete, in a bowl of warm water or run it under warm water. Do not heat on the stove or in a microwave. This can cause hot spots (as mentioned above) and can be damaging to those live cultures we discussed in the beginning (pre and probiotics). Once baby has fed from the bottle of previously frozen breast milk you may keep it at room temperature for up to 2 hours. Any longer than that and you run the risk of harmful bacterial growth. NEVER refreeze human milk.
Another popular question I have come across is: "Can I freeze my breast milk after it has been in the refrigerator for 4 days?"
YES YOU CAN!!!! Think of it as a use or freeze by date.
For those moms heading out of the house or back to work where a refrigerator or freezer is not available, you may bring an insulated cooler with ice packs to store breast milk during travel. Most storage bags and bottles can store anywhere from 4-8 ounces. Some hospitals may even offer disposable plastic storage bags or disposable bottles in which you can start storing your breastmilk in as soon as your baby is here.
What if I have breast milk leftover after I feed my baby?
Once you have thawed your breast milk or have fed your baby off of that bottle you want to finish it within 2 hours. If you have leftover breast milk, even small amounts, we recommend discarding it or saving it for a milk bath. Breast milk has hundreds of benefits, not just for feeding your baby. A milk bath can help with eczema, dry skin, baby acne and more. The reason for this is that once the baby's siliva makes contact with the breast milk, enzymes start to break down the milk for digestion.
What If I make more or less than what my baby is currently eating? Can I mix the all the milk from that day together?
Great questions! We do not recommend mixing same day milk in the same storage container. However, as a mom who exclusively pumped for my NICU grad, I would pour my milk into premeasured storage bottles to make life a little easier when it came time to feed. For term babies you may not have this issue but I found it helpful for other caregivers of our baby as well.
This is valuable information to give to your infant's daycare as well. For example, I would pump and freeze my fresh breast milk, then I would bring small amounts to my daughter's daycare before it was needed so that it had time to thaw for the next day. You may also purchase sanitizing steam bags which will ensure the limitation of harmful bacteria.
Some moms have reported that their stored breast milk may have a strange breast milk smell. This does not mean that the breast milk is bad or spoiled. The ABM states this is caused by the oxidation of fatty acids. The Academy of Breastfeeding medicine also brings up a good point! We eat foods which give off similar smells all the time such as eggs, fish, and cheeses. Therefore, we should not assume our baby will reject the milk that may have a different smell.
Appreance of stored breast milk can also be alarming if you don't know what to expect. Breast milk is high in fats to help the baby grow and develop. Fat weighs less that most of the other components in breast milk which causes it to float to the top. This is normal. It may look like a broken Hollandaise sauce or gravy. Not to worry! Once you have poured it into the bottle it will mix right back up. Breast milk should not be shaken.... so a stirring motion is a good idea.
Sanitation is very important when handling breast milk. You want an area free of germs. Wash your hands before touching any of the breast pump parts before and after pumping. Plastic bags such an sandwich bags or freezer bags are not recommended. The thicker plastic used for breast milk storage bags ensures that your milk steas clear of any contamination. Another popular option are glass containers.
As always, if you have any further questions or concerns about breast milk storage, breast health, the health of yourself or your baby please contact your healthcare provider, your baby's Pediatrician or Lactation Consultant.