The American Academy of Pediatrics (AAP) recommends exclusively breastfeeding for the first six months…followed by another 6 months of breastmilk and solids. Over the course of those 12 months, your milk will change to match your baby’s needs. We’re breaking down the basics of breastmilk and breastfeeding…and, it’s pretty fascinating!

What is Colostrum?

Immediately following delivery, many babies are sleepy for 6-12 hours, but then their appetite starts to perk up. By the next day, it will feel like you're feeding around the clock…typically every 2-3 hours. The “milk” baby is getting is called colostrum, sometimes referred to as “white blood,” is slightly yellow in color and rich with high-immunity, white blood cells, proteins, antibodies and all the nutrients babies need in the first days of life.

When Does Your (Transitional) Milk Come In?

Within 2-4 days your colostrum will turn into “transitional milk.”The American Pregnancy Organization tells us that, “Transitional milk occurs after colostrum and lasts for approximately two weeks.” This milk has high levels of fat (more than colostrum), lactose (milk sugar that helps build the brain), and water-soluble vitamins.

How do you know your milk came in?

When you wake up on the 3rd or 4th day and feel like your chest just doubled in size…your milk came in. You will hear women talking about how their breasts feel engorged and very firm initially. Over the next 1-2 weeks, this regulates as you and your baby get into balance.

If you have twins, your breasts will rev up to make double the amount of milk! On the other hand, giving bottles too often (with breast milk or formula) usually reduces a baby’s suckling…and reduced sucking usually leads to a reduction of a mom’s milk supply.

Having said that it’s fine—and a good—idea for nursing moms to offer one bottle of a couple of ounces of breast milk once a day, after you have achieved a couple of weeks of very good, comfortable nursing.

What is Mature Milk?

Don’t let the name mislead you…mature milk is the final milk your body will produce from here on out. It is made up of two parts: foremilk and hindmilk.


Foremilk is the milk that flows from your breasts in the first few minutes of feeding. It contains tons of refreshing water with vitamins, milk sugar and protein.


Hindmilk—like its name sounds—means the milk that comes later in the feeding, behind the foremilk. It is believed that this richer, fattier milk makes babies sleepier.

Both are important. About 90% of your milk is actually water (needed to keep your baby well hydrated) and the other 10% is made up of key nutrients to keep baby healthy and growing, like special, brain-building carbohydrates, proteins, and fats.

How Breasts Make Breast Milk

Breasts create their “liquid gold”—drop-by-drop. It accumulates constantly…all day and night. These drops are stored in a collecting system under the breast’s areola. As the collecting systems fill—the breasts swell, feeling heavy and full.

Within a few seconds of the baby latching and starting to suckle, the breast has a “let down.” The let down experience is very different from one mom to the next. Some feel a warm tingle, almost electricity! And others barely feel anything. Some moms take a minute or two to let down (if your nipples hurt a lot, that may slow the let down even more). Some moms notice the milk drips out…and for others it sprays out!

Note: Some people refer to nursing moms as Earth Mothers. But I think a better name is… Galactic Goddess! That’s because the ancient Greeks invented the words galaxy and galactic out of their word for milk…gala. Legend has it that milk spraying out of the breasts of the goddess Hera spurted across the heavens and formed the stars in the Milky Way, our galaxy.

Are your breasts making enough milk? If your breasts feel heavy when you wake up, occasionally leak, if you can hear your baby gulping a bit at the start of a feed and your baby is peeing more than 6 times a day (clear or very light yellow)…your breasts are probably making plenty of milk. (Always check with your baby’s health care provider if you have ANY concerns!)

How to Prepare Your Breasts for Breastfeeding

  • Take a breastfeeding class
  • Find a lactation consultant
  • Buy a nursing bra that is comfortable but supportive, avoid underwire
  • Research breast pumps and speak with your insurance about how to receive one for free

How Often Should You Nurse…And For How Long?

Now that you know the “what?” on breastfeeding, here’s the “how often?” and “how long?”

In our culture, it’s normal for newborns to nurse 10-12 times a day. No wonder it can feel like you just finished one feed…when it’s time for the next! But, did you know that moms throughout the history of humanity always plunked their babies on the boob for thirty, forty or one hundred times a day! (That actually gives a flow of nutrition that more closely mimics the constant food delivery system babies enjoy in the womb.)

We're not saying “you should” feed that often, but we are saying giving 10-12 feeds a day is your baby being as reasonable as possible. That why the longest you should expect your new baby to sleep at night—even in SNOO—is 4 hours.

And, once the baby is on the breast, some experts advise moms to nurse 15-30 minutes…on one side only. They believe staying on one side is required for babies to get the rich hindmilk, which makes them feel full and satisfied…and brings on sleep (the way a heavy meal makes us drowsy).

That one-sided strategy works for some, but it often leaves babies…underfed. Why? Well, it turns out that milk flow is fastest during the first few minutes, but then reduces to a slow drip. (That’s why your baby may have noisy gulping for a few minutes, and then settle into a slow, quiet, relaxed pattern.)

In fact, a long feeding will tire babies out with little milk consumed the last 25 minutes of a 30-minute feed. That causes many babies to cry again in hunger in just 30-60 minutes.

For this reason, switching sides every 5-7 minutes works best for most babies. That’s when your baby’s gulping will slow to a slower pattern of swallowing. That’s a good time to take him off, burp him, and offer the other side.

Don’t worry, when you switch sides the hindmilk won’t disappear. While he is on the 2nd breast, the first will refill with hindmilk…ready to satisfy your little one when you return him for a second 5-7 minute round.

This way of feeding usually gives babies a few extra ounces every day, which helps them sleep better at night. And, most hindmilk left in the breast at the end of feeding will just hang around and boost the calories of the next meal!

What to Do if your Breasts are Producing Milk Before Delivery

It can be a bit of a shock when you start lactating before your sweet baby makes their debut but don’t worry—it’s normal to have a little bit of production beforehand.

There’s no need to pump or stimulate to try to bring the colostrum out. In fact, if you stimulate your breasts too much, you can bring on early labor! So don’t worry about pre-birth lactation. Just think of it as a warmup lap before the big race.

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Disclaimer: The information on our site is NOT medical advice for any specific person or condition. It is only meant as general information. If you have any medical questions and concerns about your child or yourself, please contact your health provider.