What is hindmilk?

Breastmilk is high in fat to help your baby grow. When milk is produced in the breast, the fat can “stick” in the milk ducts. The milk ducts carry the milk to the nipple. When you pump or feed, the fat in your milk ducts takes time to “unstick” and mix with the rest of the milk.

The lower fat and calorie milk in the start of the pumping session is called “foremilk.” The higher fat and calorie milk at the end is called “hindmilk.”

What is hindmilk pumping?

Hindmilk pumping is using separate bottles to collect the foremilk and the hindmilk. You will only feed your baby the hindmilk.

This may be an option for you if:

  • Your healthcare team feels that your baby needs extra calories.

  • You produce a lot of breastmilk (called “high supply” or “oversupply”). This is about 1 liter (33 ounces) of breastmilk per day.

Supplies Needed

  • A breast pump

  • Several storage bottles (depending on the size of the bottle and your milk supply)

Directions for Separating

  1. Begin pumping. When your milk is flowing steadily for about two minutes (or as directed by your provider) turn off the pump. Label the container “foremilk,” with the date and time.

  2. Attach a separate container to the pump. Keep pumping until your milk flow stops. Pump for two more minutes (or as directed by your provider). Label the container “hindmilk,” with the date and time.

How will I know if I separated it correctly?

When you are learning how to pump hindmilk, your baby’s healthcare team will help make sure that it’s working. There are three main ways to know that the milk has been separated correctly.

Crematocrit testing: The Milk Lab can take a sample of your hindmilk and test it to see if it is higher in calories than your normal breastmilk.

Color of the milk: Hindmilk will appear creamy and white. Foremilk will look clear and watery.

Your baby’s growth: This is the best way to know if the feeding plan is working. Your baby’s weight and length will be followed closely by their healthcare team.

Can I save my foremilk?

Yes. Your foremilk can be frozen and may be used later when your baby no longer needs extra calories.

Breastmilk Storage Table