Ok friend, never heard of foremilk and hindmilk? Good. You probably don’t need to! But if you have, you may have learned the wrong things. Foremilk and hindmilk are terms that circulate often in the lactation world. They refer to the milk that empties out of the breast during milk expression. Hindmilk gets a lot of “praise” for being the rich, fatty milk that baby needs. Foremilk is often believed to be less attractive or desirable because it is waterier, less fatty, and less nutritive. Basically, there’s this odd hindmilk vs foremilk debate – and really, our babies need all of it.
What are foremilk and hindmilk?
Foremilk and hindmilk are NOT different types of milk. The lactating body produces milk – that’s it. But depending on how long it has been since the breasts have been emptied, the fat content can be different. Foremilk is the milk that is released at the beginning of a feed or pumping session. It is usually higher in volume and lower in fat. Hindmilk is the milk released at the end of a feeding or pumping session. It is usually lower in volume and higher in fat. In one particular feeding/pumping session, the hindmilk (the milk at the end) will have a higher fat content than the milk initially released (the foremilk).
Wait, can you explain that again?
More or less, all of our breastmilk is a fatty substance. But as milk is produced in our breasts, the fattier components of it (sometimes called globules) stick to the walls of the breast alveoli and to each other. As a baby starts to eat or a pump starts to express, the fat is ‘stuck’ farther back in the ducts. The first milk that comes out is often less fatty, as much of the fat is still ‘stuck’ behind. As the session continues, the fat makes its way down and out of the ducts.
How do I know my baby is getting to the hindmilk?
The move from foremilk to hindmilk is a gradual system that continuously occurs throughout an expression. Kelly.mom teaches you to consider a hot water faucet. When you initially turn on the tap, the water moves from cold, to cool, to warm, to warmer, to hot – the fat in the breasts does the same thing. For those more visual, consider the different types of cow’s milk we can purchase – we can move from skim, to 1%, to 2%, to whole, to heavy cream. Again, this is a gradual change with no clear delineation between non-fatty milk and fatty milk.
Understanding the way this system works matters! To ensure baby get’s to the fatty milk, let them fully empty one breast before moving them to the next. It’s also important to allow them to dictate when they are finished as opposed to having them on a clock. Breast emptying ensures that they DO get to the fattiest milk available.
How long does it take to go from foremilk to hindmilk?
This system is NOT a switch. There is no specific time where the fat content changes over. This is what I believe is one of the biggest misunderstandings floating around about foremilk and hindmilk. The fat content of the milk being released IS ABOUT THE TIME BETWEEN FEEDS OR PUMPING SESSIONS, OR THE EMPTINESS OF THE BREAST. When our breasts are full (meaning the time between expressions has been longer), you will see that waterier, low fat milk as the foremilk. Then, the milk will progressively move to the fattier hindmilk. However, when our breasts are emptier (meaning the time between expressions has been short), you will see a fattier, richer milk released right away. This is because the fat globules are already low in the ducts and ready to be expressed in the milk. In this scenario, the foremilk is rich and fatty!
Should I throw away foremilk?
When breastfeeding, many now use milk catchers like the Haakaa, Elvie Catch or Elvie Curve. These are tools that help catch any foremilk that may leak from the breast not being nursed on (and yes, I love them too)! Because these tools catch only the intial foremilk, there’s a worry that this isn’t good milk to give to baby because it isn’t fatty milk.
But wait – you know that isn’t always true now, right? Foremilk does frequently gets a bad rap for being the watery non nutritive milk and hindmilk gets all the glory for being the “good,” fatty milk. One last reminder to let go of this misconception. It isn’t true. Like I’ve mentioned, if there’s been a long time between expressions, the hindmilk at the end will be fattier than the foremilk from beginning. But, if the time between feeds/sessions has been short, that foremilk will be rich and fatty and creamy too (and that’s what will be in that milk catcher)!
In general, I would also suggest to you that you should never throw breastmilk out! There is always a way to use it.
Foremilk and hindmilk: in real life
Still feeling a little confused? Let me see if I can help. Let’s go back to the water faucet example from Kelly.mom. If it has been awhile since we’ve turned on the hot water tap, it takes some time for the water to heat up. However, if you just used the hot water tap, it will warm up a lot quicker AND be warmer right from the start. The fat content of our milk is the same. When our breasts are REALLY full (or its been a long time since the ‘tap’ has been used) it takes some time to get to the rich fatty milk (the hot water). But when our breasts are emptier (the ‘tap’ was more recently used), the fatty milk (warm water) is right there from the start and quickly gets fattier (hot water).
Here’s 2 quick real life examples from my own experiences:
1. Normally, baby wakes up at 2 am and 6 am to feed. For whatever reason, baby skips both of these wake-ups and sleeps until 7am. I have to pump at 6am because I’m so full and uncomfortable. That foremilk is super watery (sometimes more bluish in color) because my breasts are so full and that fat has been pushed way back in the milk ducts (a much longer time between feeds).
2. I eat some lactation cookies for breaskfast and feed my baby around 7 am every day. I then pump around 8 or 830. This pumped milk is VERY fatty right away (the foremilk is fatty!). This is because my breasts are emptier and there has been a much shorter time between expressions.
What is foremilk and hindmilk imbalance?
Many worry about something called a foremilk-hindmilk imbalance. While this can occur, it is not nearly as common as it may seem. This foremilk and hindmilk imbalance happens when baby keeps filling up on waterier, less fatty foremilk and isn’t getting enough of the richer fattier hindmilk. This can cause the baby to take in too much lactose and not be taking in enough fat. Though both foremilk and hindmilk do have nutritive value and purpose, baby does need the richer milk from the end of the feed too.
What causes it?
Imbalance is most commonly associated with those who have an oversupply of milk, babies who switch frequently back and forth between breasts, or those who cut feedings short based on the clock. It’s not very common in exclusive pumpers, since all the milk from each expression is always combined together.
Signs that baby may have an imbalance:
- Baby is fussier than normal
- Baby is gassier than normal or becomes gassy
- Baby seems to have symptoms of colic (frequent crying, multiple days in a row)
- Baby is passing consistently green, frothy poops
Foremilk and hindmilk imbalance: how to fix it
A foremilk/hindmilk imbalance can usually be corrected. Amanda from Exclusive Pumping discusses some of the ways you can try to correct any issues at the bottom of her article here. If you have any concerns about your supply and the subsequent effect on baby, please reach out to your provider.
The takeaway on foremilk and hindmilk
Probably not. Like I mentioned at the beginning, this is talked about a lot but I’m not so sure we need to hear so much about it. While things can change from feed to feed, research indicates that if you don’t cut feedings short, over the course of the full day babies receive the amount of fat they need and gain weight. For the vast majority, this topic can truly be one we can more or less forget about.