What Causes Low Milk Supply?

Why is My Milk Supply Low?

Despite breastfeeding being a “natural” way to feed, it can also be a source of anxiety and uncertainty. There is a culture heavily reliant on concrete, numerical affirmation, both from the family and the medical community, that, with the slightest concern, occasionally equates to leading the mother to supplement or even stopping altogether. Understanding the breastfed baby and “supply,” arguably the most common word used regarding breastfeeding, how it’s established, and what is adequate, would relieve many of these anxieties and aid in mothers’ self-efficacy.

In this article, we will cover why milk supply is low, is it low milk supply, and ways to build supply thresholds back up.

The Early Weeks: Establishing Enough Milk?

From the start, breast milk production is directly influenced by the frequency of feedings and the effectiveness of the latch or pump in expressing milk. The first 4 weeks of postpartum life is the timeframe in which the body is assessing "how many mouths" it's feeding (i.e., single baby or multiples) and developing the threshold or maximum potential of breast milk supply; it can fluctuate too.

We can positively impact breast milk supply with skin-to-skin time in the first 30-60 minutes after birth, uninterrupted unless medically necessary. Birth weight will not change significantly to wait until after, and a lot of the screening by the health care provider can be done while on the mother's chest, i.e., skin color, heart, and respiratory rates. This uninterrupted time allows the mother to aid in the baby's heart rate and temperature regulation and allows baby to get the colostrum right away instead of prolonging and possibly making it too upset to try. The colostrum will be a concentration of sugars (energy) and immune help right away.

Breastfeeding momBreastfeeding mom

Avoiding pacifier use in the beginning is important, too. Newborns typically wake up only to eat, so they're hungry if they are awake and fussy. Average feeding times and frequencies are a way to gauge expectations but are not meant to establish rigid feeding schedules, especially in the beginning. Hence the term: feed on demand. This requires trust in your body and your baby's instincts. We also need to know feeding cues to do this. As previously stated, the first cue for a newborn is waking up.

Understanding that milk will not be flowing and gushing out in the first few days but will transition slowly from a small, concentrated form to more volume later will help set expectations appropriately rather than assume you don't have enough milk to feed your baby right away. It can take up to 5 days to transition! Cluster feeding will speed up this process while also providing adequate energy.

If, after 5 days, milk has not noticeably transitioned, we need a lactation professional to assess for adequate breastfeeding support. You can notice with fuller breasts, let down of milk, watching stool color change in the dirty diapers from black to green to yellow, and if hand expressing or pumping, the milk will change from yellow to white when transitioned. An assessment will look at feeding positioning, how the baby nurses, how the baby sleeps, and assess the mother for health concerns/history, such as history of Polycystic Ovarian Syndrome (PCOS), diabetes, and how her labor and delivery went. 

Maintaining Enough Milk

Delayed or difficulty feeding can result in Jaundice and too much weight loss. In addition, Jaundice will make the baby more tired, too tired to feed effectively, which can further the cycle. Colostrum can be spoon- or syringe-fed to treat Jaundice if too tired or unable to feed effectively, and it works faster than light therapy alone.

Weight loss is normal, up to 10%, but too much may lead to the need for supplementation. If supplemented, there is an increased risk of becoming too reliant, and that time away from the breast will increase, resulting in lowered breast milk supply. Weight gain can be checked before and after breastfeeding to determine how many ounces are being drunk per session and whether or not the baby is getting enough milk for its age, which will also guide how much to supplement where needed. A board-certified lactation consultant should provide this. (IBCLC)

Poor Latching

Sometimes latching issues slip right under the radar, but it can be a key factor in low supply issues. A good latch is a complex and intricate motor function in the baby, and something as simple as an uncomfortable feeding position or as complicated as a tongue-tie anomaly can be the obstacles.


The latch needs to have both lips sealed around the breast, no tucking. This allows a vacuum seal to form, lowering the suction strength needed and energy expenditure to complete the feeding. The tongue needs freedom of movement to not stick out, but to rise and contour their palate, not just the tip of the tongue. This allows a wave-like motion to draw the nipple in a back, away from the gum line, to essentially coax milk out and down the throat. If the head is turned to try latch, versus facing directly, this motion is inhibited in varying degrees. If to retrain the move there is a tongue tether (ankyloglossia), this may need to be clipped and have rounds of therapy tent of the tongue that would’ve otherwise happened while still in the womb.

Cuties diapers without MedicaidCuties diapers without Medicaid

If the latching has not been effective, we will most certainly see a direct correlation in breast supply capabilities. If not enough has been removed to complete feedings, not enough will be replenished, no matter how much we try to remedy with food, supplements, etc.

Is it Low?

Sometimes we want to use a breast pump to see what our milk looks like and if we think it's enough. What is enough, and is this an effective tool to gauge that?

In short, breast pumps are not an effective way to determine if one has enough milk or an established milk supply. Moreover, it's unreliable because so many don't respond to a pump the same way since so much of the response to release milk is a hormonal and emotional one in conjunction with the baby.

Perception VS Reality

Once milk has matured to the white milk we think of, babies will need approximately an ounce per hour, so about 24 oz a day, and will gradually increase up to 36-38 oz a day when closer to 6 months of age. This looks like 2-3 ounces of feeding if a baby feeds every, on average, every 2-3 hours. This is quite different from the 4-6 ounces we see in formula feeding. Breastmilk changes concentration with the growing baby without the need to increase in volume (ounces). If a mom does not understand this and pumps 3 ounces, her perception may be that she’s not producing enough milk when she pumped a feeding amount.


But, since we don’t need to use the pump to gauge supply, what are ways to determine if we have enough milk?

  • Check diapers. No, really! What goes in, must come out, and it tells a story
    • Has the milk transitioned
    • Poop: Newborns pass stools almost after every feeding, 1-3 months, will slow down dramatically
    • Wet diapers: Newborns should pass urine one or more times in the first 24 hours after birth. After that time, he or she should urinate:
    • 2-3 times in the next 24 hours
    • 4-6 times a day during the next 3-4 days
    • 6-8 times a day on (and after) day 5
    • Generally speaking, one wet diaper per day of life until day 7
  • Infant body language can tell us a nice story as well. Balled fists indicate hunger in many infants and tension in the rest of the body. They should relax after a full feeding.
  • Weighted feeds: as previously discussed, a lactation consultant can weigh the baby before and after feeding on calibrated infant scale to accurately determine the transfer of milk, giving near exact ml or oz ingested.

Is It Breast Size?

Breast size/cup size will not determine the mother’s breastfeeding ability. It is merely how much fat tissue is in the breast that determines cup size. The alveoli and other mechanics of the breast can be present in even the smallest of breast tissues. Breast capacity will sometimes determine how often the baby needs to be fed, but it’s rarely a measurable difference. Mothers who have had a breast removed due to breast cancer can still feed exclusively from the remaining breast! Breast enlargement /augmentation is seemingly harmless on breastfeeding and breast supply capabilities, so long as nerves around the nipple are not damaged and can be stimulated. On the flipside, breast reduction can be problematic if too much tissue is removed, removing the ally and milk ducts. It’s important to discuss long-term goals with your surgeon before performing such surgeries.

First Things First: Get Acquainted With an IBCLC

These individuals have thousands of hours in training and education on all things breastfeeding, while other medical professionals may only have a baseline on understanding lactation. This is ultimately a healthcare problem for the baby and the breastfeeding mom and should not be treated lightly.

Once we have determined the cause for low supply, care plans may include:

  • Taking a “breastfeeding vacation,” which would mean spending a few days at home focusing only on feeding and feeding frequently.
  • Looking at and addressing maternal health: breast health and history, placental retention, hormonal health, and history, etc, along with making proper referrals.
  • Infant oral anatomy assessment and screening.
  • Positioning pointers and comfort measures for the mother and the breastfed baby, such as achieving a good latch.
  • Allowing the baby to cluster feed if previously not doing so.
  • Determining if supplementation is needed, for how long, and plans to wean off properly from it. Otherwise, anytime a feeding is replaced by a bottle, and not properly monitored by a professional, it's a missed opportunity to stimulate the body to produce more milk.

About the Author

Ashley Georgakopoulos is an International Board Certified Lactation Consultant (IBCLC) that specializes in the clinical management of breastfeeding and an expert in the field of lactation. Ashley is from Knoxville, TN, and is a mother who has dealt with the obstacles and joys of breastfeeding. As the owner of Genesis Lactation, she educates families, connects them to resources, and helps the next generation be as healthy as possible: nutritionally and sustainably.

Information provided in blogs should not be used as a substitute for medical care or consultation.

Information provided in blogs should not be used as a substitute for medical care or consultation.


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