Breastfeeding is a gift you give your child, that lasts a lifetime. Breastfeeding, also known as nursing, is the feeding of babies and young children with milk from a woman's breast. It not only has many health benefits for your baby but also helps you, the family, and society. Breast milk, also known as mother's milk, is the milk produced by mammary glands located in your breasts. Breastfeeding supplies all the necessary nutrients in the proper proportions and protects your baby against allergies and diseases. 

While breastfeeding should start within the first hour of your baby’s life, there are certain situations or times when you might not be available to breastfeed your baby. It is in these times that expressed breast milk comes to your rescue. Expressed breast milk is the best food for your baby when you're not around.

Expressing milk means squeezing milk out of your breast so you can store it and feed it to your baby later. You can express milk by hand or with a breast pump. You might want to express your breast milk if you are traveling for an emergency, if your breasts feel swollen and full, or when your baby is not able to suck well but you still would like to give breast milk. 

Expressing and storing your breast milk can be a stressful process if you are not clear about various details. Read on to find answers to commonly asked questions about expressed breast milk.

1. What kind of container should you use to store expressed breast milk?

Before expressing or handling breast milk, wash your hands with soap and water. Then store the expressed milk in a clean, capped glass or hard plastic, BPA-free container. BPA stands for Bisphenol A and is an industrial chemical that is used to make certain plastics. You can also use special plastic bags designed for milk collection and storage. 

However, breast milk storage bags might tear, leak, and become contaminated (to make impure by adding a harmful substance) more easily than hard-sided containers. For extra protection, place the bags in a hard plastic food storage container with a tightly sealed lid. Don't store breast milk in disposable bottle liners or plastic bags designed for general household use.

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

Using waterproof labels and ink, label each container with the date you expressed the breast milk. If you're storing expressed milk at your baby's child care facility, add your baby's name to the label. Place the containers in the back of the refrigerator or freezer, where the temperature is the coolest. 

If you don't have access to a refrigerator or freezer, store the milk temporarily in an insulated cooler (a portable container with a layer of insulation to ensure that it keeps foods cold). Fill individual containers with the milk your baby will need for one feeding. 

You might start with 2 to 4 ounces (59 to 118 millilitres), and then adjust as needed. Also consider storing smaller portions, around 1 to 2 ounces (30 to 59 millilitres), for unexpected situations or delays in regular feedings. Breast milk expands as it freezes, so don't fill containers to the brim. 

3. Can you 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, thoroughly cool the freshly expressed breast milk in the refrigerator or a cooler with ice packs before adding it to previously chilled or frozen milk. Don't add warm breast milk to frozen breast milk because it will cause the frozen milk to partially thaw (become liquid or soft as a result of warming up).

4. How long can expressed breast milk be kept or stored?

How long you can safely keep expressed breast milk depends on the storage method. Consider these general guidelines for healthy infants:

  • Room temperature. Freshly expressed breast milk can be kept at room temperature for up to six hours. However, use or proper storage within four hours is optimal. If the room is really warm, the limit is four hours. 

  • Insulated cooler. Freshly expressed breast milk can be stored in an insulated cooler with ice packs for up to one day.

  • Refrigerator. Freshly expressed breast milk can be stored in the back of the refrigerator for up to five days in clean conditions. However, use or freezer storage within three days is optimal.

  • Deep freezer. Freshly expressed breast milk can be stored in the back of a deep freezer for up to 12 months. However, using the frozen milk within six months is optimal. 

Keep in mind research suggests that the longer you store breast milk — whether in the refrigerator or in the freezer — the greater the loss of vitamin C in the milk. Breast milk contains plenty of vitamin C. Vitamin C, also known as ascorbic acid, is critical for your baby’s immune system, iron absorption, and for the healthy production of various tissues.

It's also important to note that breast milk expressed when a baby is a newborn won't as completely meet the same baby's needs when he or she is a few months older. Also, storage guidelines might differ for preterm (infant born before 37th week of pregnancy), sick, or hospitalized infants. 

5. How do you thaw frozen breast milk?

Thaw the oldest milk first. Place the frozen container in the refrigerator the night before you intend to use it. You can also gently warm the milk by placing it under warm running water or in a bowl of warm water. Also, don't heat a frozen bottle in the microwave or very quickly on the stove. Some parts of the milk might be too hot, and others cold. 

Some research also suggests that rapid heating can affect the milk's antibodies (proteins needed by your baby’s immune system to fight foreign substances). While further research is needed on whether previously frozen milk that's been thawed can be frozen again and safely used, many experts recommend discarding thawed milk that isn't used within 24 hours.

6. Does thawed breast milk smell or look different from fresh breast milk?

The colour of your breast milk might vary, depending on your diet. Also, thawed breast milk might seem to have a different odour or consistency than freshly expressed milk. It's still safe to feed your baby. If your baby refuses the thawed milk, you can try shortening the storage time.

Talk to your paediatrician/obstetrician to understand more about expressing and storing your breast milk. Also, check with your doctor about how to express breast milk with your hand or the breast pump if you are uncomfortable or not sure of the correct technique.

Disclaimer: This article is written by the Practitioner for informational and educational purposes only. The content presented on this page should not be considered as a substitute for medical expertise. Please "DO NOT SELF-MEDICATE" and seek professional help regarding any health conditions or concerns. Practo will not be responsible for any act or omission arising from the interpretation of the content present on this page.