Breastmilk Storage: Tips and Guidelines

As a new mother, one of the most precious gifts you can give your baby is breast milk. It's not just a source of nourishment but also a way to provide essential antibodies and immune-boosting components. However, what do you need to do so you can store that liquid gold for later use? In this blog, we'll explore the key aspects of expressed breast milk storage, including the right containers, storage guidelines, and some unique considerations.

Storage Containers

When it comes to storing breast milk, the choice of containers matters. Experts recommend using containers specifically designed for human milk storage. Rigid polypropylene containers are the gold standard because they preserve more nutrients and immunological components compared to other containers. If polypropylene containers are unavailable, Pyrex or glass containers are a suitable alternative. While plastic storage bags are an option, they are less ideal due to the risk of nutrient and immunological losses, as well as the potential for leakage.

Storing Breast Milk

Breast milk can be stored at different temperatures, depending on how soon you plan to use it. Here's a breakdown of storage recommendations:

• Freshly expressed breast milk can be kept at room temperature for 6-8 hours, but only in a room with a temperature of 26°C or cooler. If it's warmer, store it in the fridge.
• In the refrigerator, breast milk can be safely stored for up to 72 hours at 4 degree. Ensure it's placed in the back of the fridge for consistency in temperature.
• For long-term storage, breast milk can be frozen. It can be stored for up to 2 weeks in the freezer compartment of a fridge/freezer combination (-15°C), 3 months in a separate-door freezer (-18°C), or 6-12 months in a deep freezer (-20°C).
• Thawed breast milk should be used within 4 hours (if left on the bench) if it's not warmed or within 24 hours if kept in the refrigerator. Never refreeze thawed breast milk.

6 Important Tips for Breast Milk Storage

1. Only add cold breast milk to cold breast milk. Cool breast milk in the refrigerator before combining it with another batch.
2. Always label containers with the date and time of expression to ensure you use the oldest milk first.
3. Prioritize using previously expressed breast milk to avoid the need to refreeze it.
4. Breast milk can be stored at room temperature for 6-8 hours but is safest in the fridge for up to 72 hours.
5. Never refreeze breast milk that has already been thawed.
6. Avoid shaking thawed milk; instead, gently swirl it after warming.

What Does Freezing Do to Breast Milk?

Freezing breast milk has some effects on its components. Freezing can destroy living white cells like T- and B-lymphocytes. While minerals in breast milk remain stable, freezing can cause the fat components to break down during the freezing and thawing process. It's essential not to shake thawed milk. 

Maximizing Your Milk Volume

To maximize milk expression, consider combining breast massage with hand expression or pumping. Start with hand expression to stimulate a letdown and alternate between pumping and massage/hand expression until the flow slows down. This approach can help ensure thorough milk removal.

Antenatal Expressing

In some cases, expressing breast milk before your baby is born may be necessary. Colostrum, the first milk, is crucial for protecting the baby from pathogens. Expressing breast milk from 36 weeks gestation onwards may be recommended if there are concerns about separation from the baby or potential health issues. We’ll cover this in more detail in our next blog.

The Unusual: Dealing with Lipase Activity

Sometimes breast milk can develop a soapy or fishy aroma and taste due to high lipase activity. This doesn't make the milk unsafe but might be unappealing to the baby. You can prevent this by scalding the milk before storage.

In conclusion, proper breast milk storage is vital for ensuring your baby gets the best nutrition possible. Use the right containers, follow storage guidelines, and consider unique factors like lipase activity to provide your baby with the healthiest start in life. For more detailed guidance, consult with a lactation consultant or healthcare professional.

Author: Mary Dowswell (IBCLC)