Breastmilk composition and the hindmilk/foremilk myth

The information that there are 2 (or more) types of breastmilk is poor, outdated and very confusing for families. A lack of understanding around breastfeeding often means parents are told that babies need to stay on one breast per feed to ensure they ‘get to the hindmilk’.

The reality is in fact that as long as a baby feeds frequently and actively from both breasts, the make-up of the milk is going to be perfectly made for that baby, and not something we can, or should engineer. All milk is good! It’s worth remembering that it is the volume of breastmilk that is the important factor in a baby gaining weight and stimulating more milk production.

While there are not 2 distinct types of milk, the milk composition does change as a feed goes on. It is true that as your breasts fill up, the fat in your milk does cling to the inside of the ducts as the pressure builds, and there is an element of separation that occurs. Using both breasts frequently will mean that the fat levels are more consistent throughout the whole feed. Think of a hot tap where the fattier milk is the hot water. When you first turn on the tap, the water runs cooler before getting warmer, and then hot. Now turn off the tap. If you were to turn it on again the water would still be warm, if not hot. But, if you were to leave it a greater period of time, the water would be cool again, and you’d have to wait for the hotter flow.All milk is valuable and important to a baby in terms of hydration, nutrition and comfort.

Following your baby’s cues at the breast and watching for their active swallows can be an effective way to ensure your baby is getting a bigger overall volume of milk per feed. Everyone’s breasts have a different storage capacity. Think of a car going on a long journey, a car with a smaller fuel tank will need to stop and refuel more frequently than one with a larger capacity, but that’s not to say the car can’t make the journey! This is similar to why some babies need 2 or more sides per feed, whereas others may be full after 1. 

Breastmilk supply works on a demand and supply basis, so the more that is removed, the more your body will replace. Keeping baby on one side for a certain period of time, rather than watching their active drinking, will certainly compromise milk removal, and therefore the continuation of the supply.

If you have concerns around your milk supply, or baby’s weight gain, please do reach out to an IBCLC.