Milky Monday: Letdowns and the Question of Fat in Breastmilk

Happy Milky Monday! As promised, this week we’ll talk about the foremilk/ hindmilk issue and how fat is released in your milk.

First, let’s discuss the letdown. Also known as the Milk Ejection Reflex, the letdown is when the milk sacs in your breast contract and force the milk through the milk ducts and out of the nipple. It’s triggered by hormones released by various stimuli like holding your baby, hearing your baby (or any baby) cry, nipple or breast stimulation (baby suckling or breast pumping), thinking about your baby, or even just setting up to nurse or pump.

Some people feel a tingly or pins-and-needles sensation when their milk lets down, and some may feel only their first letdown, every letdown, or none at all. There are usually 2-4 letdowns per nursing session, but you may not realize it unless you pay close attention to baby’s suckling pattern. Babies tend to have faster sucks with little swallowing when working to trigger a letdown, and slower, longer sucks with frequent swallowing once the milk lets down.

The milk sacs that are responsible for producing and storing the milk in your breasts are lined with fat cells. Fat cells are thicker and sort of “sticky,” so they’re released slowly throughout the feed. This is where the foremilk/hindmilk issue comes into play. The milk in the first letdown of the feed will have lower fat content than the second, third or fourth letdowns, but it will have a higher volume of milk. Subsequent letdowns will have a lower volume of milk released, therefore the amount of fat in that milk will be a greater percentage of that milk. In other words, the less milk there is in your breast, the higher the amount of fat within that smaller amount of milk.

There is no magic amount of time or letdowns that determines when “foremilk” turns to “hindmilk,” so I don’t lend a lot of weight to those terms. What many people attribute to “too much foremilk” tends to be an issue of forceful letdown and oversupply. If you’re concerned about your milk or your baby’s ability to transfer milk, please reach out. I am available for virtual visits anywhere, and home visits within and near Ashtabula County.