Breast Milk Production – How Does It Work?


Breastfeeding and breast milk supplyUnderstanding the basics of breast milk production is an important part of breastfeeding and pumping. The more you know about how your body works, the more you’ll be able to get things moving in the right direction. Breast milk production is a natural occurrence in a woman’s body. In fact, your body was preparing for the birth of your child before you were even born. Wrap your head around that one! My point is, because breast milk production, and breast milk supply is such a constant worry among breastfeeding mothers, having an arsenal of knowledge is the best way to combat those fears.

The Basics of Breast Anatomy

breast milk productionFirst of all, let me give you a basic idea of what it looks like inside your breast. Your breasts are made up of a combination of fat cells, supportive tissues, and milk glands. During pregnancy, those milk glands expand, causing your breasts to swell and grow. Pregnancy hormones cause milk ducts to grow inside your breasts, creating a network of branches all linked together. The milk ducts continue to grow and multiply, then they begin to branch off into smaller ducts called ductules. At the end of each ductule a cluster of small sacs appear. These sacs are called alveoli. I like to compare the breast milk production system to a tree. The trunk of the tree is your nipple and areola. The large branches growing out from the tree are your milk ducts, and the smaller branches that grow from the larger branches are the ductule, and the leaves are the alveoli. Now, I know it’s a bit more complicated than that, but for the sake of this article try to imagine a tree inside your breast. This entire milk duct system is usually fully operational by the 2nd trimester, so if Baby comes early your body is prepared.

How is breast milk produced?

Breastfeeding and breast milk productionNow that you kind of have an idea of what makes up a breast, let’s talk about breast milk production. I’m going to once again simplify it a little bit, and start out by saying that it’s all about the hormones. There are these two main hormones, one is called prolactin, and the other is called oxytocin. When prolactin is released, the alveoli (the leaves at the end of the branches) start by taking proteins, sugars, and fat from your blood supply and convert it into breast milk. This first step in breast milk production is usually completed by the 2nd trimester. Now, once your baby has been delivered, and once the placenta has been expelled, your body will go through a sudden drop in estrogen and progesterone levels. When this happens your prolactin level shoots through the roof, signaling your body to bump up the breast milk production. At this time you may notice your breasts swelling to make room for all the new milk. The next step is milk ejection, commonly referred to as “let down”. In order for your body to release the breast milk from the internal alveoli, the other hormone called oxytocin must come into play. This is how it works. When your baby first latches on and starts suckling, those two hormones are released into your bloodstream. More prolactin, which is the one that converts proteins, sugars, and fat into breast milk, and then oxytocin. Oxytocin is what releases the breast milk from the internal alveoli, by causing the cells around the milk filled alveoli to contract and squeeze. The breast milk then empties into the ductule which then empties into the larger milk ducts and continues on down to the nipple where your baby is patiently waiting.

The entire process of breast milk production is simply amazing, but it can also be very nerve-racking as well. One of the most common fears among breastfeeding mothers is whether or not their breast milk supply will be enough.  Just remember, the more often you feed your baby, whether your breastfeeding or pumping, the more hormones will be released, and the more milk your body will produce. Keep those hormones pumping through your system, get plenty of rest, and drink lots of fluids. Good Luck!

Related Articles:

Breast Milk Supply – Is Your Milk Supply Really Low?Low milk supply is perhaps the most common concern among breastfeeding mothers. It’s important to have realistic expectations when it comes to breastfeeding and breast milk supply…

Breast Milk Supply – Pumping and BreastfeedingGetting a good start in the beginning is extremely important when establishing your breast milk supply. Research tells us that the first 2 weeks are extremely important…

Which Breast Pump Is Best For You?Your lifestyle is the deciding factor when it comes to choosing which breast pump is best for you. Are you a stay-at-home mom, or a working mom? How much time will…


We may earn a commission for purchases using our links. Learn More.