By Caroline Steele, board-certified lactation consultant, a board-certified specialist in pediatric nutrition, and registered dietitian at CHOC Children’s
CHOC has board-certified lactation consultants as well as certified lactation educators available to assist breastfeeding or pumping moms. Many of our other staff members, including nurses, dietitians and developmental specialists, can also assist families with breastfeeding and pumping, and many have specialty lactation training.
Because nutrition is one of the most important factors in a baby’s health, CHOC Children’s provides lactation services to mothers who wish to breastfeed or pump while their baby is in the hospital.
Here are answers to some of the most common questions we receive on frozen breast milk safety.
Can breastmilk be frozen?
Yes, breastmilk can be frozen and should be frozen if it won’t be used right away (similar to what you would do with other foods).
What is the safest way to freeze breastmilk?
- For preterm or hospitalized infants, it is generally recognized that milk that will not be used within 48 hours after it is pumped, should be frozen. For healthy babies at home, it is possible to store freshly pumped milk in the refrigerator for 5 days before needing to freeze it.
- Milk should be frozen in rigid plastic bottles or plastic bags specifically designed for breastmilk storage. Plastic bags are not recommended for hospitalized infants because they are prone to leaking and are more difficult to handle in the hospital setting.
- Freeze milk in volumes that the baby would normally eat so that once it is thawed, none is wasted.
- Never add freshly pumped milk to a bottle already containing frozen milk. Newly pumped milk should go into its own container.
How long can breastmilk be frozen?
- If freezing/storing breastmilk in a combination refrigerator/freezer unit, the milk should be stored in the back of the freezer to keep it from being exposed to temperature fluctuations when opening and closing the freezer door. In this type of unit, the milk may be stored 3-6 months.
- If freezing/storing breastmilk in a deep freezer that can maintain a temperature at or below zero degrees Fahrenheit, it may be stored for 6-12 months.
- Once frozen milk has been thawed, it must be used within 24 hours or discarded.
I’m giving my baby frozen breastmilk. Are there any risks I should know about?
- It is best to use the oldest pumped milk first to prevent milk from being frozen too long.
- Some of the immune enhancing properties of breastmilk are decreased over time when milk is frozen. However, the risk of bacterial contamination of milk that has been kept in the refrigerator too long and not frozen, far outweighs the downside of freezing milk.
- Sometimes there are slight changes in the taste and smell of milk that has been frozen due to the enzymes naturally present in breastmilk. Those changes are not harmful and don’t matter to most babies. However, some babies do have a noticeable preference for milk that has not been previously frozen.
