When Does a Pregnant Woman Start Producing Milk?

For many mamas-to-be, tender breasts are one of the earliest signs of pregnancy, signaling the many big and exciting changes to come.

And that’s just the beginning!

Your breasts will continue to change throughout your pregnancy.

They’ll likely grow a bit bigger, the veins in them will probably become more noticeable, and your areolas might get darker.

But what about breast milk? When does a pregnant woman start producing milk? And what is colostrum, and how is it different from milk?

Let’s take a look.

In this article: 📝

When does lactation start?

Lactation is the medical word for the process of producing breast milk, and it happens while your little one is still inside you.

Most mamas will start producing milk between weeks 12 and 18 of their pregnancy.

By then, your breasts are probably starting to feel a bit bigger than normal.

This is because both the size and the number of your milk glands are increasing.

Your milk duct system will be fully developed at some point during your second trimester, so that you’re ready to feed your baby even if they arrive a little early.

While you’re pregnant, usually during your last trimester, your breasts might start to leak.

Don’t worry, mama, this is totally normal!

It’s a good thing, in fact, it means that your body is getting ready to welcome your hungry baby into the world.

You might notice that your breasts leak when your nipples are stimulated, such as when you have sex or if they rub against your bra while you exercise.

It’s also normal if your breasts don’t leak, by the way, so don’t fret if this isn’t something you experience.

You’re just likely to have cleaner bras – win!

If you do leak, you might notice that the liquid is yellow or orange.

That’s because it isn’t mature breast milk but rather something called colostrum.

What is colostrum in pregnancy?

Colostrum is your baby’s superfood.

It’s full of protein and antibodies that do wonderful things for your little peanut, including providing them with excellent nutrition and helping to develop their immune systems.

It can be clear, creamy, white, or even orange in color and is usually thick and quite sticky.

Colostrum is easy for babies to digest and is very good for their gut. It works as a laxative and helps them to clear their first poop, which is called meconium.

When do pregnant women start lactating “proper” breast milk?

When you feed your baby for the first time (what a thought!), you’ll be feeding them colostrum rather than mature breast milk for the first two to three days.

For some mamas, it might take longer than this, so don’t worry if your body does its own thing.

Every pregnancy, birth, mama, and baby is different.

You might notice when your milk “comes in”, although this is usually a gradual change rather than something that happens quickly.

Your breasts might start to feel fuller, heavier, or more swollen, and your baby might start to behave a little differently when they’re guzzling.

Breastfeeding is an adventure all on its own, and (we’ll say it again) everybody’s journey is unique.

Now that you know a little bit more about where your breast milk comes from, you might want to find out more about the next steps.

The blogs below are here to help you, mama:

🍼 31 Best Breastfeeding Tips for New Moms

🍼 Your Essential Formula Feeding Guide

🍼 7 Breastfeeding Positions to Try

🍼 A Quick Guide to Pumping