Separating Hindmilk to Help Your Baby Grow

Important information:

If your baby needs more calories to help them gain weight, you may be able to separate your milk while pumping to provide higher fat milk. The amount of fat in your milk can vary during a pumping or breast/chest feeding session and at different times of the day. Your milk changes over time as your baby gets older.  Some parents naturally make milk with higher fat content. The foods you eat will not change the amount of fat in your milk.

You can increase the fat and calories in your milk by making some changes to the way you pump.

To separate your milk to provide higher fat milk, you will need to produce about 1/3 more milk than your baby eats every day. At each pumping session, you will remove the first 1/3 of the milk that you pump from each breast and save the rest.

The first milk that comes out of your breast/chest is called foremilk. Foremilk contains protein and other nutrients, but it is lower in calories and fat. As the breast/chest is emptied, the amount of fat and calories in the milk gets higher. When you are very full there is less fat in the milk. The milk collected after you remove the foremilk is called hindmilk.

It is helpful to know how much milk you get from each side at each pumping session. You can plan to remove the first 1/3 that you pump. For instance, if you normally pump 60 ml on each side, you will remove 20 ml of foremilk. Foremilk can be frozen for later use. It is still very nutritious. It is just lower in fat and calories than hindmilk.

Instructions for separating your milk:

1. Have extra milk storage containers ready.

2. Begin expressing your milk with the breast pump. About two minutes after the milk starts flowing steadily, turn the pump off, pour this milk into a container and label it foremilk. This should equal about 1/3 of the usual amount that you pump. Some parents notice that their milk changes from being thin and watery to rich and creamy.

3. Continue pumping until your milk flow stops, then pump for 2 more minutes. It is helpful to massage your breasts/chest while you pump as this adds more fat to your milk. Be sure to thoroughly empty because the drops of milk at the end are the highest in fat. Store this milk in bottles labeled hindmilk.

Separating your milk may be different at different times of the day. Remove more foremilk when you know you get larger volumes and less when you normally produce lower volumes. If you are directly breast/chest feeding, the same technique can be used to remove foremilk before you start feeding. Massaging your breasts/chest prior to feeding also increases the fat in the milk. Your baby will start feeding at the breast/chest with higher calorie milk to help them gain weight.

If you have questions, concerns or are experiencing pain, ask to speak to a provider who specializes in lactation support.

Reviewed June 2024 by Lauren Davidheiser, MS, RDN, IBCLC, LDN and Meghan Devine, BSN, RN, IBCLC