When Does Milk Come In – Pregnancy, Colostrum and After Birth

When does milk come in?

When Does Milk Come In – A Breast Milk Discussion

It’s the day after birth and you’re relishing those cozy cuddles. Only… when you breastfeed you don’t feel like your baby is getting much. So you wonder… when does your milk come in? 

Don’t start to worry yet! Every mom is a little different but milk usually doesn’t start coming in until after the first few days. 

This article will address when your milk comes in – from colostrum to transitional milk and finally mature milk! Keep reading for what to expect with your milk coming in during pregnancy and after birth. 

When does breast milk come in?


Before we start, I want to address a few things about milk supply. 

Breastfeeding moms number 1 reported worry is their breast milk supply. Even moms that have an adequate supply often find themselves worried. So before you worry, here are a few things to consider: 

  • Pumping doesn’t give you an accurate idea of your supply. 
    • Babies are MUCH more efficient than breast pumps. Some moms pump after their baby breastfeeds and don’t get much, if any. That’s completely normal. 
    • Some moms pump between feedings or they’ll pump to give their baby a bottle. They worry when they only produce a few ounces. But if their baby was to breastfeed instead, they’d be able to get a lot more milk. 
  • Colostrum, the first milk you produce, isn’t produced in large quantities.
    • Your baby doesn’t need much colostrum in the first few days to get full. So don’t worry about your milk supply when you are only seeing colostrum at first. In time when your mature milk comes in, your supply will increase. 
  • Pregnancy doesn’t give you a good indication of your milk supply. 
    • Some women leak colostrum during pregnancy. Other women don’t leak at all. Colostrum leaking during pregnancy doesn’t mean you’ll produce more. 
    • Don’t try and pump during pregnancy. It won’t affect your milk supply and it could send you into preterm labor. Milk supply really isn’t affected until after birth because of hormones (we’ll talk about that later). 

When does milk come in during pregnancy?

The milk that comes in during pregnancy is called colostrum. It’s the first stage of milk you’ll produce, and starts it’s production in the 3rd month of your pregnancy. 

When does a pregnant woman start producing milk? 

Your breasts are preparing for producing milk as soon as you get pregnant. Your pregnancy produces hormones that tell your breasts they will need to feed a baby soon. 

Throughout your pregnancy, your breasts grow. The milk ducts in your breasts sprout and branch, getting ready to make milk. The reason your breasts start to grow during pregnancy is because of high levels of progesterone and estrogen. 

By the time you reach your third month of pregnancy, your breasts have some milk-like secretions within them. And finally, during your second trimester, colostrum is present within your breasts. 

During pregnancy, your body releases a hormone called prolactin. It’s the “milk-making” hormone. But the high levels of progesterone in your body during pregnancy prevent your body from using the prolactin to make milk. That’s why you don’t see mature milk until after you give birth. 

When does milk start leaking during pregnancy?

Some women start leaking milk during pregnancy as early as the 3rd month of pregnancy. 

Other women don’t leak at all during pregnancy. They might worry they won’t produce milk after their baby is born, but that’s very rare. 

The amount of milk you do or don’t leak during pregnancy has no effect on the amount of milk you will have when your mature milk comes in. 

If you do leak during pregnancy, it’s called colostrum. Colostrum is the first milk you produce and it’s yellow, sticky, and packed full of antibodies and nutrients. Consider using a milk saver if you are leaking colostrum during pregnancy – then you can start your milk stash! 


When does colostrum come in? 

Colostrum comes in during the second trimester of pregnancy, whether you notice it leaking during pregnancy or not.  

Immediately after birth, if your baby suckles they will be eating colostrum. Just a small amount is enough for your baby for the first feeding, even half a teaspoon. 

You’ll produce colostrum for about the first 4 days after birth until you start producing mature milk. As you transition to producing mature breast milk, your milk supply will have small amounts of colostrum in it for about the first 2 weeks. 

When does your milk come in?

Your milk comes in between days 2 and 5 after birth. It starts as colostrum, and gradually transitions into mature milk. 

After you give birth, your body goes through drastic hormonal changes (one big reason us women experience postpartum depression). Your progesterone decreases rapidly, and your prolactin increases. 

With your progesterone decreasing, the prolactin circulating in your body is now able to do its job (remember, progesterone prevented prolactin, the “milk-making” hormone, from making milk during pregnancy). 

Because of the quick hormonal changes, your milk will start coming in between 30 and 40 hours after birth. 

But many moms don’t notice the changes right away, and some don’t recognize their milk coming in for 5 or 6 days. 

Moms that have more than one child may start to produce milk earlier. With subsequent children, you may produce more milk as well. First-time moms tend to report their milk coming in later, and may produce less. 

When does mature milk come in after birth?

The first 4 days after birth, colostrum is produced mostly. From days 4 to 10, transitional milk is made and then by day 10 you should be producing mature milk

But just because these stages have a name, doesn’t mean it’s different kinds of milk. It’s more of a continuum of changes with your milk gradually transitioning from colostrum and into mature milk. 

The colostrum starts out as a yellow, sticky and thick liquid. Your transitional milk will look like a mix between colostrum and mature milk. It’s thinner, but still has more of a yellow tint to it. Your mature milk will look more what you’d expect milk to look like – it’s thinner and white in color. 

Mature milk consists of foremilk and hindmilk. Foremilk is thinner and has a blueish tint to it, while hindmilk is creamier with more of a yellow tint. For the rest of the time you breastfeed, you will produce mature milk consisting of foremilk and hindmilk. 

When does breast milk come in after birth?

Signs Your Milk is Coming In 

Here is how to know when your milk comes in:

  • You’ll have breast fullness and possibly engorgement.
  • Milk changes from thick and yellow to thinner and white (more “milk-like”).
  • You may start to leak milk. 
  • Your baby’s poop changes from dark blackish green to mustard yellow.
  • Your baby changes the way they eat (cluster feeding less, gulping more).

When does the milk come in? A chart.

Sometimes it helps to see it organized. This chart shows when you can expect your milk to come in, how much your baby should eat per feeding, and how many poopy diapers to expect per day. 

Diaper count and weight gain are the best ways to tell if your baby is getting enough breast milk during the first 6 weeks. Your baby should have the number of poopy diapers as days old they are until day 4. So 1 on day 1, 2 on day 2, 3 on day 3, and 4 or more on day 4. Then until your baby is 6 weeks old, they should have 4 or more dirty diapers per day. Around 6 weeks, some babies’ bowel habits change so after that, it’s important to continue seeing your pediatrician to monitor your baby’s weight. 

When does breast milk come in chart.

When does milk supply regulate?

Your milk supply should regulate between 4 and 6 weeks after your baby’s birth. The best way to regulate your milk supply is to feed your baby on demand, and avoid using pacifiers, bottles, or supplementing for at least 4 weeks. 

Make sure your baby is latching on well, gaining weight, and has plenty of poopy diapers. Breastfeeding isn’t always easy starting out, but if you stick with it, it’ll get easier for both you and your baby. 

What if my milk isn’t coming in 5 days after birth? 

If your milk doesn’t start to come in within 5 days after birth, it could be caused by: 

  • Hormonal issues (PCOS, thyroid dysfunction).
  • Retained placental fragments. 
  • C-section.
  • Premature baby.
  • Traumatic birth or extended labor.
  • Not establishing breastfeeding within first hour or first days.
  • Stress or illness.
  • Blood loss.
  • Insufficient glandular (breast) tissue.

The most important thing to do is see your doctor. If you have retained placental fragments of a hormonal imbalance, your doctor will be able to help you so you can breastfeed. 

Make sure your baby is getting enough to eat, you may need to supplement with formula even if it’s only temporary. Work closely with your pediatrician to make sure your baby is getting what they need. 

When does colostrum come in?

No Breast Milk After Delivery: What To Do

First, rule out any medical issue that may be causing it. Work closely with your doctor to determine what may be the cause. Once you’ve ruled out a medical condition, these tips can help establish breast milk supply after delivery: 

  • Have the right expectations. 
    • Some moms start to feel their milk supply come in by day 2 or 3 while others take until day 5 or 6. Try not to freak out if you are one of the later ones, just make sure your baby has enough dirty diapers and is eating enough. 
  • Try to breastfeed within the first hour after birth. 
    • One study showed that breastfeeding within the first hour after birth resulted in a higher milk supply.
  • Breastfeed early and often the first few days after birth.
    • The interesting thing about the study (above) is that the moms that didn’t establish feeding in the first hour didn’t have a difference in supply whether they waited longer than 6 hours. So, if you didn’t get the first feeding in the first hour, just feed your baby often and you have a good chance of having a normal milk supply. 
    • Milk supply only starts to depend on demand after the first few days. So if you got off to a rough start, it isn’t until day 3 or 4 that suckling really starts to significantly matter. Just establish breastfeeding as early as you can so your breasts get the signal to produce. 
  • Make sure you have a good breastfeeding latch.
    • A good latch will allow your baby to transfer milk and drain your breasts. Your breasts need to empty frequently to get the signal to produce more milk. If you think you need help achieving a good latch, reach out to a lactation counselor for help. 
  • Spend time skin-to-skin. 
    • Skin to skin helps regulate both mom and baby’s hormones. It also helps to establish breastfeeding and encourages a good milk supply. Cuddle and spend skin-to-skin time with your baby often. 
  • Avoid supplementing. 
    • If your concerned about your baby’s weight gain, consider pumping instead of supplementing. Be careful because pumping too much can cause engorgement – but pumping is much better for your milk supply. Supplementing can have a negative effect on your milk supply and it’s hard to stop once started. 
  • Wake baby after 3 hours. 
    • You’ve probably heard to never wake a sleeping baby. But newborns need to eat! And some of them would rather sleep than eat. Make sure you wake your baby if it’s been longer than 3 hours in the first 4 weeks. The only exception is one stretch in the middle of the night, it’s acceptable to go 4 hours – but any longer can negatively affect your supply. 

To Sum It Up: When Breast Milk Comes In

Typically, breast milk comes in within 2-5 days after birth. C-sections can result in milk coming in later.

Colostrum starts production in pregnancy, and some women notice leakage after the first trimester while others don’t.

If you are having trouble with your breast milk supply, it might help to contact a lactation counselor. I offer virtual or telephone lactation consultations, and I would love to help!

Kealy Hawk lactation consultant
Kealy Hawk, BSN, RN, CLC

Kealy is a Registered Nurse, Lactation Counselor, and most importantly a mommy! Her own baby feeding struggles gave her a passion to help moms throughout their feeding journey. She specializes in breastfeeding support and evidence-based formula recommendations. To talk with Kealy or take one of her breastfeeding or formula classes, visit https://littlebearcare.com.

When does your breast milk and colostrum come in?
When does breast milk come in during pregnancy and after birth?
When does breast milk and colostrum come in after birth or in pregnancy?

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