Breastmilk can change during a feed; Louisa Van Den Bergh of Lulubaby explains the difference between foremilk and hindmilk.

Chances are, if you breastfed, you are aware of the terms foremilk and hindmilk. For some mothers, understanding how their milk changes is crucial to successful breastfeeding. For other mums, ignorance is bliss. So what exactly are foremilk and hindmilk?

Gradual transition

Foremilk is typically described as the milk that is released at the beginning of a feed, while hindmilk comes towards the end of a feed. There is, however, no sudden switch, which is why I find these terms problematic. It is a gradual transition, similar to the way a hot water tap starts running cold but gradually warms up.

Mums can often see their milk is a different colour and consistency depending on the stage they are at in the feed. Foremilk is runnier and often more grey in hue, while the hindmilk is creamier in colour and consistency.

I often tell my mums it’s like baby is having a meal: they start with a drink, then a light starter and the main course, followed by the creamy, fat-rich pudding, which is less plentiful but highest in calories.

Why they may matter

There is some debate in breastfeeding circles as to whether mums should learn about these two terms. Are we just worrying and confusing mothers even more?

For many mothers whose babies are thriving and content, there is no reason to complicate matters. However, I think there are two important reasons why mums should be aware that there is a change in their milk, even if they can’t remember the precise terminology.

Fat content

The first reason is that foremilk is generally lower in fat content, while the hindmilk is higher in fat. The consequence is that, if a mother does not “do” one breast well but offers both for a short time, her baby may be hungry soon after feeding because they have not had the benefit of the satisfying, fat-rich hindmilk. This transition happens because, as milk is produced in the breast, fat globules tend to stick together and to the walls of the milk-making alveoli. When baby is not feeding, the milk amasses in the breasts and moves towards the nipple making them feel fuller, while the fat gets “stuck” further back in the milk ducts. As you progress through a feed, the globules are drawn down and the fat content of the milk increases.

Lactose overload?

The second reason is that foremilk is higher in lactose than the hindmilk. Lactose is an essential part of your baby’s diet and, in basic terms, most babies are born with a suitable amount of lactase, which breaks down the lactose. The problems begin if a baby is receiving too much foremilk. She will also receive higher quantities of lactose, which she may struggle to cope with. A baby that is receiving too much foremilk may be uncomfortable, in pain and windy, as well as having explosive green stools.

How long?

Not understanding that your baby needs to drain one breast fully can sometimes lead to uncomfortable, unhappy babies, which require extremely regular feeding. At this stage, mums often ask me, “How long should I feed on one side to make sure that my baby gets the right balance?” It is a good question, and one only mum can really answer. It depends on several factors including the speed of her let down, the efficacy of her baby’s sucking and how long it has been since the last feed.

This last point is important and it’s worth noting that, if it has not been very long since the last feed, the hindmilk is more readily accessed – again, a bit like that hot water tap. If you go back to it soon after you have turned it off, the water will run warm and get hot more quickly than if you left it for a long time.

You are the expert

Mums are quick to get to know their babies and how they feed. One way of checking is to see the colour of the milk and softness of the breast. For many mums, a quick squeeze of the breast will indicate how full it is and how well their baby has fed from it – something that is hard to imagine while you are pregnant but, once you are in the thick of feeding, you will understand where I am coming from.

And you can never have an empty breast. There is always something there, even if the milk is not very plentiful. While there is no need for many mums to be aware of the nature of their milk, it is helpful to be aware that there is a gradual change in milk during the feed. Mum should make sure that her baby has a good feed from one side, before offering the second side. In this way, she can ensure her baby has a full “meal”. After all, in my book, no meal is complete without pudding.