How Does Breastfeeding Work? An Explanation

Most mothers can make plenty of milk for their baby or babies. Getting breastfeeding off to the best start possible helps establish a good supply.

Once established, your milk supply is robust and in most cases you can keep making milk indefinitely as long as it’s removed well and often enough.

Nonetheless, it’s common for breastfeeding mothers to worry about their milk supply. Even before a baby is born some mothers worry if they’ll be able to make enough milk.

When it comes to figuring out whether your baby is getting enough milk or not, it’s important to rely on reliable signs and not the unreliable signs.

Having an understanding of how breastfeeding works can help you feel more confident in your ability to make plenty of milk for your baby or babies.

How Does Breastfeeding Work?

So, how does breastfeeding work? It all begins midway through pregnancy.

During Pregnancy Your Breasts Start Making Colostrum

The first milk your breasts make is colostrum. Colostrum is a thick yellow coloured fluid and a concentrated source of immune protective factors, protein and minerals. Your breasts start making colostrum from about half way through pregnancy.

During pregnancy, you have high levels of the milk-making hormone, prolactin, in your bloodstream. However, you don’t make large volumes of milk during pregnancy as there are also high levels of the hormone progesterone. Progesterone ensures the volume of milk you make remains low.

The Milk Volume You Make Increases Once Your Baby Is Born

With the birth of your placenta (third stage of labour), your progesterone levels plummet. This allows prolactin to then kick start the process of making larger volumes of milk from about 30-40 hours after birth.

Before this point, the milk you make is driven by hormones. After this point however, the amount of milk you make is determined by how much milk is removed (see ‘Supply Equals Need’ below).

Even though the onset of making larger volumes of milk begins 30-40 hours after birth, it typically takes a little longer before most mothers feel their breasts making larger volumes of milk and their milk coming in.