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Making breastmilk

Making breastmilk

Your breasts make milk in response to your baby's suckling. The more your baby nurses, the more milk your breasts will make. Knowing how your breasts make milk can help you understand the breastfeeding process.

How is breastmilk made?

Breasts often become fuller and more tender during pregnancy. This is a sign that the alveoli, cells that make breastmilk, are getting ready to work. Some women do not feel these changes in their breasts. Other women may feel these changes after their baby is born.

The alveoli make milk in response to the hormone prolactin (proh-LAK-tin). Prolactin levels go up when the baby suckles. Levels of another hormone, oxytocin (oks-ee-TOH-suhn), also go up when the baby suckles. This causes small muscles in the breast to contract and move the milk through the milk ducts. This moving of the milk is called the "let-down reflex." Learn more about the let-down reflex.

The release of prolactin and oxytocin may make you feel a strong sense of needing to be with your baby.

How do I know if I will make enough breastmilk?

Many mothers worry about making enough milk to feed their babies. Some women worry that their small breast size will make it harder to feed their babies enough milk. But women of all sizes can make plenty of milk for their baby. The more often your baby breastfeeds, the more milk your breasts will make.

Your baby's weight should double in the first few months. Because babies' tummies are small, they need many feedings to grow and be healthy. You can tell if your baby is getting enough milk by the number of wet diapers he has in a day and if he is gaining weight.

If you think you have or will have a low milk supply, talk to a lactation consultant. Visit the Finding support and information section for other types of health professionals who can help you.

Will my breastmilk change as my baby grows?

Yes. Your breastmilk changes in the days after birth and continues to change as your baby grows. Learn what will happen with your milk, your baby, and you in the first few weeks.


Milk: Your body makes colostrum (a rich, thick, yellowish milk) in small amounts. It gives your baby early protection against diseases.

Baby: Your baby will probably be awake in the first hour after birth. This is a good time to breastfeed your baby.

You (Mom): Let your baby begin the process of searching for your nipple. This baby-led way of breastfeeding can help your baby get a good latch.

First 12 to 24 hours

Milk: Your baby will drink about 1 teaspoon of colostrum at each feeding. You may not see the colostrum, but it has what your baby needs and in the right amount.

Baby: It is normal for the baby to sleep heavily. Labor and delivery are hard work! Some babies like to nuzzle and may be too sleepy to latch at first. Feedings may be short and disorganized.

You (Mom): Your body is still making colostrum. Take advantage of your baby's strong instinct to suck and feed upon waking every couple of hours to help your milk come in faster.

Next 3 to 5 days

Milk: Your mature (white) milk takes the place of colostrum. It is normal for mature milk to have a yellow or golden tint at first.

Baby: Your baby will feed a lot, at least 8 to 12 times or more in 24 hours. Very young breastfed babies do not eat on a schedule. It is okay if your baby eats every 2 to 3 hours for several hours, then sleeps for 3 to 4 hours. Feedings may take about 15 to 20 minutes on each breast. The baby's sucking rhythm will be slow and long. The baby might make gulping sounds.

You (Mom): Your breasts may feel full and leak. (You can use disposable or cloth pads in your bra to help with leaking.)

First 4 to 6 weeks

Milk: White breastmilk continues.

Baby: Your baby will now likely be better at breastfeeding and have a larger stomach to hold more milk. Feedings may take less time and may be farther apart.

You (Mom): Your body gets used to breastfeeding. Your breasts may become softer and the leaking may slow down.

What if my breastmilk supply goes down?

If you don't feel as "full" as you did in the first few weeks of breastfeeding, you may worry that you are not making enough milk for your baby. But know that the milk is still there and flowing to your baby. Usually, after a few months of breastfeeding, your body learns to make the right amount of milk for your baby.

Also, your baby may only nurse for short periods, such as five minutes at each feeding. These are not signs of lower milk supply. Your body adjusts to meet the needs of your baby, and your baby gets very good at getting milk from the breast. It's also normal for your baby to continue to nurse longer on each breast at each feeding.

What can affect how much breastmilk I make?

You may make more or less milk, depending on:

  • How completely milk is removed each time you breastfeed. An empty breast means better milk production.
  • How often you nurse or pump to remove milk. The more often you empty your breasts, the more milk your breasts will make.
  • The amount of milk your breasts store between feedings. If your breast stores too much milk between feedings (because your baby doesn't empty the breast), your breast will make less milk. If your breast is emptied, it will make more milk. It is common for one breast to make more milk than the other, and it is normal for babies to prefer one breast over the other. This can affect how much milk you make in that breast.

How can I make more breastmilk?

The best way to make more breastmilk is to breastfeed often and to empty your breasts completely at each feeding.

After emptying your breasts at each feeding, less milk builds up in your breasts between feedings.

To better empty your breasts, follow these tips:

  • Use breast massage and compression.
  • Offer your baby both breasts at each nursing.
  • Pump after nursing if your baby does not remove all the milk from your breasts. Your breasts will soften when the milk is removed. If the baby empties your breasts, then you can pump to remove milk and increase milk production between nursing sessions.

What is the let-down reflex during breastfeeding?

The let-down reflex (also called just "let-down" or the milk ejection reflex) happens when your baby begins to nurse. The nerves in your breast send signals that release the milk into your milk ducts. Let-down happens a few seconds to several minutes after you start breastfeeding your baby. It also can happen a few times during a feeding. You may feel a tingle in your breast or you may feel a little uncomfortable. You also may not feel anything.

Let-down can happen at other times, too, such as when you hear your baby cry or when you're just thinking about your baby. If your milk lets down as more of a gush and it bothers your baby, try expressing some milk by hand before you start breastfeeding.

Many factors affect let-down, including anxiety, pain, embarrassment, stress, cold, too much caffeine, smoking, alcohol, and some medicines. Mothers who have had breast surgery may have nerve damage that interferes with let-down.

How often should I breastfeed?

You should breastfeed as soon as possible after giving birth. Then, breastfeed your baby every 2 to 3 hours each day so that you will make plenty of milk. This means that in the first few days after birth, your baby will probably need to breastfeed about every one to two hours during the day and a few times at night.

Healthy babies develop their own feeding patterns. Follow your baby's cues for when he or she is ready to eat.

How long should feedings be?

There is no set time for feedings. They may be 15 to 20 minutes per breast, or they may be shorter or longer. Your baby will let you know when he or she is finished feeding. If you worry that your baby is not getting enough milk, talk to your baby's doctor.

How do I know if my baby is getting enough breastmilk?

There are many signs you can watch for to see if your baby is getting enough milk:

  • Your baby passes enough clear or pale yellow urine (see the chart below). The urine is not deep yellow or orange.
  • Your baby has enough bowel movements (see the chart below).
  • Your baby switches between short sleeping periods and wakeful, alert periods.
  • Your baby is satisfied and content after feedings.
  • Your breasts may feel softer after feeding.

From birth to 3 months old, a baby usually will gain up to 1 ounce of weight each day. Keep in mind that many babies lose a small amount of weight in the first days after birth. Your baby's doctor will check your baby's weight at your first doctor visit after you leave the hospital. Make sure to visit your baby's doctor for a checkup within three to five days after birth and then again when the baby is 2 to 3 weeks old.

To learn more, watch the video Is my baby getting enough milk? Also, talk to your doctor if you are worried that your baby is not getting enough breastmilk.

How much do babies typically eat when breastfeeding?

A newborn's tummy is very small, especially in the early days. Once breastfeeding is established, exclusively breastfed babies who are 1 to 6 months old take in between 19 and 30 ounces of breastmilk each day.2 If you breastfeed your baby eight times a day, your baby will get around 3 ounces per feeding. But every baby is a little different.

The Newborn Tummy

At birth, the baby's stomach can comfortably digest what would fit in a hazelnut (about 1 to 2 teaspoons). By around 10 days, the baby's stomach grows to hold about 2 ounces, or what would fit in a walnut.

Image of a hazelnut next to a walnut.

Typical number of wet diapers and bowel movements in a baby's first week (it is fine if your baby has more): 1 day = 24 hours*

Baby's age Number of wet diapers Number of bowel movements Texture and color of bowel movements
Day 1 (first 24 hours after birth) 1-2 The first bowel movement usually occurs within 8 hours after birth Thick, tarry, and black
Day 2 2 3 Thick, tarry, and black
Day 3 5-6 disposable,
6-8 cloth
3 Looser and greenish to yellow (color may vary)
Day 4 6 3 Soft, watery, and yellow
Day 5 6 3 Loose, seedy, and yellow
Day 6 6 3 Loose, seedy, and yellow
Day 7 6 3 Larger amounts of loose, seedy, and yellow

If you are using disposable diapers, the absorbency may make it harder to tell if the diaper is wet. Use this chart as a guide, but talk to your child's doctor if you are concerned about your child not getting enough milk.

*Source: American Academy of Pediatrics

How long should I breastfeed my baby?

The American Academy of Pediatrics (AAP) recommends breastfeeding as the only source of food for the first 6 months of your baby's life. The AAP also recommends continuing breastfeeding (after starting solid food) beyond your baby's first birthday and for as long as both you and your baby would like.3 The easiest and most natural time to wean is when your child leads the process. But how you feel is also very important in deciding when to wean.

Your decision may depend on several factors, such as returning to work, your or your baby's health, or a feeling that the time is right.

When should I not breastfeed?

While rare, your doctor may advise you not to breastfeed if you:

  • Take certain medicines, like anxiety medicine or certain migraine medicines, that are dangerous for babies and can be passed to your baby in your breastmilk
  • Have a specific illness (like HIV or active tuberculosis)
  • Get radiation therapy, though some therapies may mean only a brief pause in breastfeeding

If you take medicine or are sick, talk to your doctor before you begin breastfeeding. Medicines that are safe for you to take during pregnancy may also be safe while you are breastfeeding. But you should always check with your doctor before you start breastfeeding. Talk to your baby's doctor if your baby shows any signs of a reaction to your breastmilk, such as diarrhea, excessive crying, or sleepiness.

Should I stop breastfeeding when I am sick?

You can usually continue to breastfeed your baby when you are sick, and if your baby is sick. If you need to rest you can pump or hand express breastmilk for someone else to feed the baby. But if you are sick with the flu, including the H1N1 flu (also called the swine flu), do not touch or be near your baby, so that you do not infect him or her. Have someone who is not sick feed your baby your pumped or expressed breastmilk.

Did we answer your question about making breastmilk or feeding your baby?

For more information about making breastmilk or feeding your baby, call the OWH Helpline at 1-800-994-9662 or check out the following resources from other organizations:


  1. American Academy of Pediatrics (AAP). (2011). SIDS and other sleep-related infant deaths: Expansion of recommendations for a safe infant sleeping environment. Pediatrics; 128(5): 1030-1039.
  2. Kent, J.C., Mitoulas, L.R., Cregan, M.D., Ramsay, D.T., Doherty, D.A., Hartmann, P.E. (2006). Volume and frequency of breastfeedings and fat content of breast milk throughout the day. Pediatrics; 117(3): e387-e395.
  3. AAP. (2012). Breastfeeding and the use of human milk. Pediatrics; 129(3): e827e841.