When Does Breast Milk Come In? What to Look For and How You'll Know

The look and feel of your colostrum, or early milk, is much different from your mature, later milk - which often comes in around 2 - 5 days after your baby's birth, though every mama’s timing is different. 

When Does Breast Milk Come In?

Though colostrum production begins as early as 16 weeks pregnant and should begin to be expressed right away after birth (with some moms even experiencing occasional leakage later in pregnancy), its look and composition differs significantly from your later breast milk. This is because colostrum, or your “first milk”, plays a much different role for your baby than your later breast milk, though both forms are incredibly important to your baby’s wellness and development. Though later breast milk may take some time to “come in” after delivery, your milk production has been in the works since early in your pregnancy, so don’t worry, mama – it’ll be here soon enough!

Moms shouldn’t expect to see large milk volumes in the first few days after birth, though most newborns lose weight during this time. Both of these things are normal and expected, and your colostrum is all your newborn needs until your later milk presents. With that in mind, your later milk – or the breast milk produced as your colostrum transitions to your mature milk – “comes in” about 2 – 5 days after your baby’s birth. “Coming in” refers to the significant increase in volume and changes in composition, though this popular term isn’t necessarily accurate. This is because your colostrum is breast milk and should be fed to your baby as soon as possible after birth. When your mature milk comes in later, however, it is accompanied by some very noticeable symptoms. Many women, even first-time moms, know exactly when their breast milk has come in, mainly due to common indicators like:

  • Breast engorgement, or the feeling of fullness, heaviness, and/or firmness.
  • Swelling of the breasts.
  • Breast milk leakage, particularly overnight.
  • Flattened nipples and/or skin tightening or firmness around the areolas.

This initial engorgement – and the occasional discomfort that may accompany the first time your milk comes in – will dissipate as your body adjusts to a regular nursing and pumping routine. If your breasts are frequently engorged after your milk comes in, this is a sign that your body is working hard to produce milk and you may not be fully emptying your breasts after a nursing session – be sure to have a breast pump and breast milk storage bags on hand, so you can fully empty your breasts after and between breastfeeding your little one. Your pumped breast milk can be stored in the refrigerator or freezer, so you can start a stockpile for your little one – which can be especially helpful if your partner or another person, such as a babysitter, needs to feed the baby. Just be sure to read up on the latest breast milk storage guidelines to ensure none of your precious liquid gold goes to waste!

What Else Should I Know?

Though your body’s breast milk production is kicked into high gear within 30 – 40 hours after you deliver the placenta, your later milk coming in is dictated by the hormonal changes taking place in your body during this time. Because every woman – and every pregnancy – is different, there is a range of days during which breast milk may come in. With that in mind, there is evidence that skin to skin contact, initiating breastfeeding within 30 – 60 minutes after birth, and continuing to nurse early and often (or pumping or hand expressing your colostrum to feed your baby, if there are latching challenges) can positively impact your breast milk production.

If your breasts are very engorged, it can be more difficult for your baby to latch properly. Try softening your breasts before a feeding, such as by taking a warm shower, applying a warm compress to each breast, and/or hand expressing a small volume of milk. You can also apply a cold compress – think a bag of frozen vegetables or an ice pack wrapped in a towel – to reduce swelling and discomfort. Prevent engorgement and reduce your risk of developing mastitis or encountering eventual breast milk supply issues by nursing or pumping frequently.

If you have questions about your breast milk coming in, concerns about supply, or are experiencing difficulties getting into a regular breast milk feeding routine, talk to a lactation consultant right away. The sooner you can address any issues you may be facing, the easier it will be to minimize impact on your future breast milk production. Remember, mama, it’s common to encounter early breast milk feeding challenges – especially if you’re a first-time mom – and it may take some time for your body and hormones to adjust. After all, you just did an amazing thing by welcoming your little one into the world! The most important thing to remember is to persevere and continue finding ways to ensure your baby receives all that great liquid gold that your body is making – whether by pumping, nursing, or a combination of both. As your milk comes in and you adapt to life with a newborn, you and your baby will eventually get into a regular feeding routine. Congratulations on your new bundle of joy – and be sure to enjoy this unique bonding time together!