When Does Breast Milk Come In? 7 Important Facts

Did you know that your breasts actually start making milk before your baby is born?

From around four months pregnant, your breasts start making colostrum.

Colostrum is the first milk your baby gets after being born, and is a concentrated source of anti-infective factors, protein and minerals.

However, your milk ‘coming in’ refers to when your breasts start making large volumes of breastmilk, and the composition changes (e.g. higher lactose and lower sodium concentration).

When Does Breast Milk Come In?

Here are 7 important facts about your milk coming in:

#1: Your Breast Milk Will Come In Regardless Of Whether Your Baby Breastfeeds Or Not

Your milk coming in is driven by hormones, which means it will happen whether your baby breastfeeds or not.

During pregnancy, you have high levels of prolactin (your milk making hormone). But you don’t make lots of milk during pregnancy due to high levels of the hormone progesterone. High levels of progesterone prevent prolactin from doing its job fully.

After your placenta has come away (third stage of labour), this makes your progesterone levels plummet. In turn, this means prolactin levels (which continue to be high) can now kick into action, and start the process of making lots of milk.

#2: Your Breast Milk Will Most Likely Come In Around Day 3

For most mothers, their breast milk comes in between days 2 and 5.

Many first time mothers notice their breast milk comes in around day 3 or 4.

With subsequent babies, many mothers notice their milk comes in sooner – around day 2 or 3.

It’s important to remember that your baby gets colostrum from the very start, so you don’t need to be concerned that he is not getting anything to eat.

#3: Frequent Feeding In The Early Days Helps Build A Good Milk Supply

Ideally, your baby will have skin-to-skin time with you straight after birth, and during this time, he will receive his first breastfeed.

Thereafter, ideally you and your baby will be kept together (rooming-in) and you will continue to spend as much time as possible in skin-to-skin contact with your baby, feeding him whenever he needs to be fed. Learning hunger cues can be very helpful.

For more information about how to get breastfeeding off to the best start possible, read our article about what you need to know before the first breastfeed.

Getting breastfeeding off to the best start possible is important, because early frequent and effective milk removal increases prolactin activity in the breast, which helps you to set up an abundant and robust milk supply.

#4: Your Breasts May Feel Full, Warm And Hard

Milk production usually starts to increase between 30 – 40 hours after your placenta is delivered, but it may take a little while longer for you to notice the increased volume your breasts are making.

Different mothers feel different things in their breasts when their milk comes in. Most women experience their milk coming in as a gradual change, rather than something that happens all of a sudden.

Most commonly, mothers notice their milk coming in when their breasts feel fuller, warmer and harder. However, the degree to which different mothers feel this varies a lot. For some mothers, this feeling may be subtle (especially for women with large breasts) while for other mothers it may be very obvious and even painful.

If you happen to be expressing or leaking milk, you may notice that the milk changes from the thicker, yellow colour of colostrum to a thinner, whiter colour when your milk comes in.

If you don’t notice your milk coming in but you notice your baby’s poos changing to a lighter colour (e.g. yellow mustardy colour) by day 5, this is a good sign that your milk has come in.

#5: You May Notice Your Let-Down Reflex

The let-down reflex is where the hormone oxytocin allows the milk stored in the breasts to be released from the glandular (milk-making) tissue into the milk ducts and out of the nipple.

A baby suckling at the breast stimulates tiny nerve endings on the nipple and areola which signal for the release of the hormone oxytocin from the pituitary gland in the brain.

Some mothers don’t ever feel their let-down reflex while others feel it very strongly, especially when their milk comes in.

If you are a mother who feels your let-down reflex, you may notice a tingling sensation, a slight pain or sudden fullness in your breasts. You may notice milk leaking from the breast your baby isn’t feeding from (as the let-down reflex occurs in both breasts simultaneously). You may notice your baby’s sucking changing from a quick shallow suck to a deeper more rhythmical sucking when your let-down occurs.

#6: There Are Some Things That May Delay Your Milk Coming In

If your milk comes in later than day 3, it is said that there is a delay in your milk coming in.

Here are some possible reasons that could mean there is a delay in your milk coming in:

Birth Factors

Mother’s Health

Issues that affect a mother’s hormones may cause a delay in her milk coming in. For example diabetes,polycystic ovary syndrome, hypothyroidism, obesity.

Other Factors

Anything that impacts how well and how often milk is removed from a mother’s breasts may delay her milk coming in.

For example, if a mother is separated from her baby (e.g. baby is in special care nursery) or if her baby isn’t feeding well (e.g. due to a tongue-tie), milk may not be removed as often or as well and hence can cause a delay in her milk coming in.

#7: Don’t Lose Heart If There Is A Delay In Your Milk Coming In

If there is a delay in your milk coming in, remember that many mothers have been able to bring in a full milk supply even after a week or two (and sometimes even longer).

If it is recommended that you begin to supplement your baby with extra milk, you may find the Academy of Breastfeeding Medicine supplementation protocol very helpful.

Here are some things that can help to make your milk come in:

  • Discussing with medical or nursing staff, or a lactation consultant about what the possible cause of the delay for your milk coming in is. There may be things that can be done to help rectify the situation (e.g. if retained placental fragments are the issue, the milk usually comes in normally once the fragments are removed).
  • See a lactation consultant. A lactation consultant can undertake a thorough assessment to work out an individualised plan to get breastfeeding working well for you and your baby.
  • Ensure your breasts are frequently and effectively drained – at least 8 times every 24 hours. Ideally, this would be achieved by feeding your baby, but if your baby happens to not be feeding well, then expressing may need to occur. Before your milk comes in, hand expressing is the mainstay of expressing. Once your milk has come in, using a hospital grade electric pump (and finishing up with hand expressing) is ideal.
  • Frequent skin-to-skin contact with baby can also help with milk production.

Breastfeeding is our biological norm and thus our bodies are designed to make milk in a way that is suitable for newborns. Their tiny bellies are around the size of a marble on their first day of life, so it makes perfect sense that our mature milk doesn’t come in for a bit of time. Remember that though the milk doesn’t ‘come in’ immediately following birth, you are likely to make the perfect amount of colostrum.

Renee Kam IBCLC in Breastfeeding. Last updated on August 11, 2015

Posted on April 24, 2016 .