Understanding your milk supply

Article Summary

Your breasts rely on your baby to fine-tune milk production so that you produce the right amount of milk to meet your baby’s needs. The more milk your baby removes from your breasts, the more milk you will make. Despite views to the contrary, breasts are never truly empty. Milk is actually produced nonstop—before, during, and after feedings—so there’s no need to wait between feedings for your breasts to refill. In fact, a long gap between feedings actually signals your breasts to make less, not more, milk. 

An understanding of milk production makes it easier for mothers to identify potential problems and possible solutions. You can be sure that your baby is getting enough to eat if he has lots of poopy and wet diapers and is gaining at least 5 ounces each week during the early months. There are steps mothers can take to increase their milk supply if necessary. Simply ask your baby’s heath care provider to recommend a lactation consultant, La Leche League Leader, or breastfeeding peer counselor in your community.

Imagine that you are the owner of a grocery store and you have a new product you want to put on the shelf. You’ve heard good things about this product and you anticipate that people will want to buy it, but you aren’t sure how much inventory to carry. How can you tell whether it is a popular item? What if the demand for the item wanes over time?

You might start with a small order. And if the demand grows, you might order more. If the product continues to fly off the shelf, you’d probably stock your warehouse. And when the sales start to drop off, you’ll stop ordering the item altogether. 

This is similar to how the breasts decide how much milk to make. Breasts are designed to be efficient milk factories. The customer in this case is your baby, and the “sales” are the milk he gets from your breast at each feeding. Your breasts work under the principle of supply and demand. Your baby demands milk, and your breasts supply it. He wants more? The breasts step up milk production. He eats less? Production slows down. 

Placing the order 

So what triggers the initial order to start making milk? Most of the time, it is pregnancy and the accompanying hormones that stimulate breast tissue growth. The placenta produces estrogen and progesterone, and these two hormones keep the breasts from going into full production. After your baby's birth and delivery of the placenta, the levels of these hormones drop and prolactin kicks in signaling the breasts to make lots of milk over the next few days. 

At this point, your breasts rely on the baby to help fine-tune the milk order so the breasts can produce just the right amount of milk. The baby removes milk from the breast—the more milk he removes, the more quickly that milk is replaced. 

“Empty” is a relative term, however, as is “supply.” Breasts are never really empty, since milk production continues non-stop, even while the baby is feeding. Unlike the grocery store analogy where customers empty the shelves and then must wait for the factory to deliver more product to the store, milk is always being produced. There’s no need to wait between feedings for the breasts to refill—in fact, a long wait between feedings tells the breasts that the baby needs less milk and production slows down.

Maintaining the order 

As long as milk is removed from the breast, more milk will be made to replace it. As your baby grows and begins to eat other complementary foods in addition to breast milk (usually around 6 months of age), he’ll take less milk from the breast and production will slow. This marks the start of the weaning process—a process that can last anywhere from a few weeks to a few months to years. Once your baby weans completely, the breasts will eventually stop production altogether, although many women find that they can still express drops of milk months after weaning is complete.

Troubleshooting supply issues 

If making milk is so simple, why do so many women worry about supply issues? Understanding the way it is supposed to work helps identify potential problem areas—and their solutions. In order for a woman to have the amount of milk her baby needs, when he needs it, the following are necessary: 

  • A fully functioning breast—one with enough glandular tissue and working nerves to get the job done. The good news is that most women have enough glandular tissue. And most women have the working nerves needed as well. One exception are women who have had breast surgery that involved cutting the nerves and ducts around the areola (darker part of the breast around the nipple). While these women may be able to produce all the milk needed, they need to monitor their baby’s weight gain just in case the nerves aren’t signaling the brain to make milk.
  • A baby who is willing and able to latch on to the breast. Most babies can breastfeed just fine if given the chance. Some may need a little help at first: some skin-to-skin contact with mom, some gentle waking for sleepy babies, and some repositioning to make sure the baby has a good latch. Some babies may have anatomical issues to overcome, such as tongue-tie (when the frenulum or tissue between the tongue and lower gum is so short the baby can’t latch on effectively) or cleft lip or palate (when the lip and/or roof of the baby’s mouth does not form properly and leaves a hole in either). Sometimes these conditions require surgery; in the meantime, mothers should be encouraged to express their milk to maintain their milk supply and feed their babies their expressed milk using an eyedropper, teaspoon, hollow-handled medicine spoon, or cup.
  • Milk removal. Just because a baby is on the breast doesn’t mean he is actively removing milk from the breast. The most common solution to this problem is re-positioning the baby and checking carefully to ensure that he has a proper latch. If your baby can’t remove milk from the breast (this is sometimes the case with preterm infants with no fat pads in their cheeks or a sick infant who has been separated from his mother and fed with artificial nipples and bottles), you can express your milk while getting help with milk removal issues.
  • Access to the breast. Because the breast factory bases production on the baby’s needs, it works best when the baby has free access to the breast, and is allowed to feed on request. Mothers will need to learn their baby’s subtle hunger cues (such as moving their hands to their mouth, making smacking noises, or sucking on their fingers) and respond accordingly. Crying is a late sign of hunger and babies who reach this stage of hunger may have more difficulty latching onto the breast or they may fall asleep after breastfeeding for only a minute or two. Rigid schedules make it much more difficult for the breast to respond to the baby’s needs. Plus, skipping or delaying feedings can cause breasts to become engorged (overly full), which in turn slows the flow of blood to the alveoli (milk-producing cells) and decreases milk production.

Common milk supply worries

Sometimes moms worry unnecessarily about their milk supply because they misinterpret signals and cues, often based on previous or oft-spoken about bottle-feeding experiences: 

  • Baby nurses “all the time”. “All the time” to a new mom may mean more frequently than expected. Because breast milk is digested so easily, breastfed babies eat frequently, at least 8 times every 24 hours (in the beginning). And breastfeeding is also a source of comfort, and satisfies a baby’s need to suck, so he may want to breastfeed up to 12 times a day (or even more). On rare occasion, a baby nursing “all the time” is an indication that he is not efficiently removing the milk from the breast.
  • Baby suddenly wants to breastfeed longer and more often. As babies grow, they often have frequency days in which they just seem to want to breastfeed all day long. Usually this signals a growth spurt, which typically occurs around 3 weeks, 6–8 weeks, 3 months, and 6 months of age, but can happen at any time. Follow your baby’s lead and breastfeed on request. Don’t worry that you are not making enough milk. The more milk your baby takes from your breasts, the more milk you will make. There is no need to supplement with formula or expressed breast milk during these growth spurts. After a few days of frequent breastfeeding, your milk supply will increase to meet your baby’s needs.
  • Baby doesn’t breastfeed as often as he used to. As your baby gains experience at the breast, he can get his fill faster. But a decrease in frequency of feedings may also indicate a nursing strike. Usually these are temporary and caused by teething, illness, or a change in routine. Continue to offer the breast, but do not insist if your baby refuses. Until the strike ends, you will need to hand express or pump your breasts to relieve fullness and maintain your milk supply.
  • Your breasts are softer and aren’t leaking as much. Right after birth, breasts have extra fluid and more milk than is needed. As some of that extra fluid goes away and the breasts begin to supply just what your baby requests, they will feel softer and leak less. 
  • Baby is fussy. There are many reasons a baby might be fussy and fussiness is not necessarily an indication of hunger or problems with breastfeeding. The late afternoons are common times for fussy periods, and it usually has nothing to do with your milk supply.
  • You can’t get much milk if you pump. No breast pump is as good as a baby when it comes to milk removal. Our bodies are designed to respond to a baby’s suck, not to hard plastic and metal mechanical devices, so it may take some practice to trigger a let-down reflex with a breast pump. Always feed your baby from the breast whenever possible and pump whenever your breasts are full or whenever it’s convenient—before, after, or in between breastfeedings. Since milk is continually being produced, pumping whenever it’s convenient will enable you to collect and store milk for later use.

Milk supply problems 

The best way to know what is going in the baby is to look at what is coming out—i.e., lots of poopy and wet diapers! After the first week or so, look for six or more wet diapers and four or more poopy diapers each day. Your baby will also be gaining about 4–8 ounces each week for the first few months. Remember, your breasts will make milk to replace milk your baby drinks, matching what your baby needs. If you aren’t sure whether breastfeeding is going well, talk to a lactation consultant, La Leche League Leader, or breastfeeding peer counselor at your local health department. They can check your positioning, your baby’s latch, and give you tips for increasing your milk supply. In addition to working with a lactation consultant, try the following: 

  • Offer the breast more often. 
  • Avoid using pacifiers. 
  • Don’t use supplements unless your baby’s health care provider decides they are medically necessary. 

The more you know about how your milk-making system works, the less likely it is you’ll encounter any supply issues. Talk with your health care provider if you have concerns about your milk supply.

Last updated October 22, 2018

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