The science behind the much debated 'milk supply'

Fluff free information about breast milk, supply, and the science behind it.

Breast milk production is a complex biological process regulated by a combination of hormonal, physiological, and environmental factors. Despite ongoing misinformation about a mothers supply or 'lack thereof', breast size, feeling of fullness, babies length of feeds or pump output is in no way a good measurement to determine if your baby is getting enough milk.

Old wives tales aside, before understanding 'supply' we should really know how our bodies produce milk. For every human with these fabulous fleshy things we call boobs, it's probably important to have an overview of the science behind breast milk production (and then what can cause low milk supply).

 

The science behind breast-milk production

Prolactin is produced by the pituitary gland in response to the stimulation of the breast's nerve endings during breastfeeding or pumping, Prolactin stimulates the milk-producing cells (alveoli) in the breast to produce milk.

Oxytocin is released in response to nipple stimulation and is responsible for the "let-down" reflex, which causes the milk to flow from the alveoli into the milk ducts, making it available for the baby.

 

An evidence based understanding of milk supply

1. You make what baby takes

Breast milk production operates on a supply-and-demand principle. The more frequently and effectively a baby feeds or the more often a mother pumps, the more milk her body produces to meet the baby's needs. Frequent breastfeeding sessions help maintain milk supply, as the removal of milk from the breasts signals the body to produce more.

I highly recommend not listening to the common suggestion to feed your baby every 2 hours. Feeding on-demand and whenever your baby shows feeding cues is the best way to establish a good supply throughout your feeding journey (and this includes night feeds).

 

2. Your boobs care about how you treat yourself

High levels of stress can interfere with milk production. Stress hormones can inhibit the release of prolactin and oxytocin, impacting the milk ejection reflex and milk production.

Proper nutrition and hydration are also essential for milk production. Dehydration and an inadequate diet can lead to low milk supply.

So, this is a reminder to check in with yourself and ask for the support you need.

(medical reasons like insufficient glandular tissue PCOS and thyroid disorders, can impact milk production as well as some medications).

 

3. Breastfeeding is a dance between mama and baby

An improper latch or ineffective breastfeeding technique can reduce milk transfer, leading to a perceived low milk supply.

It's also important to know that babies born prematurely may have difficulty breastfeeding initially as their sucking reflexes are still developing, and their mothers may experience delayed milk production. In this case it is essential to have a good lactation expert guiding you on your journey.

 

4. Insufficient Breast Stimulation

If a mother doesn't breastfeed or pump frequently enough, her body may not receive enough signals to maintain or increase milk supply. Things like scheduled feeding and night weaning are not recommended for at least the first 4 months as your supply will likely drop. The golden rule, feed on demand!

 

5. Hormonal Changes

Hormonal changes, such as those associated with menstruation, pregnancy, or weaning, can temporarily affect milk supply. But don't worry, if you continue to feed on-demand, your milk will follow after some patience. 

Now for some truth bombs...

 

 

Debunking 'breast-milk supply' myths

There are several common myths and misconceptions surrounding a mother's breast milk supply. It's important to debunk these myths to provide accurate information and support for breastfeeding mothers. Here are some of the most prevalent myths:

Myth: The size of a mother's breasts determines her milk supply.

Fact: Breast size has no direct correlation with milk production. The amount of glandular tissue in the breast is what matters for milk production, and this can vary greatly among individuals.

Myth: If a baby feeds frequently or for long periods, it means the mother doesn't have enough milk.

Fact: Frequent and lengthy feedings are often normal, especially in the early weeks of breastfeeding. They help establish a good milk supply and may be due to the baby's growth spurts or need for comfort.

Myth: Supplementing with formula is necessary because a mother's milk is not enough.

Fact: Most healthy mothers produce enough milk to meet their baby's nutritional needs. Supplementing with formula without medical necessity can decrease milk supply and interfere with breastfeeding success.

Myth: If a mother is not experiencing pain or discomfort, she doesn't have enough milk.

Fact: Lack of pain or discomfort during breastfeeding is not an indication of low milk supply. Many mothers produce enough milk without experiencing discomfort.

Myth: Breastfeeding mothers should avoid certain foods.

Fact: While some foods may cause temporary fussiness in babies (due to changes in the taste of breast milk), most mothers can eat a wide variety of foods without affecting their milk supply or the baby's well-being. Allergies are relatively rare.

Myth: If a mother has a stressful or emotional day, her milk will become "bad."

Fact: Temporary stress or emotional fluctuations do not make breast milk "bad." Breast milk remains a healthy and nutritious option for the baby.

Myth: Once a mother's milk supply is established, it will remain constant.

Fact: A mother's milk supply is dynamic and responds to the baby's needs. It can fluctuate based on factors like growth spurts, illness, or changes in feeding patterns.

Myth: Pumping output is an accurate indicator of milk supply.

Fact: Pumping output can vary widely among individuals and may not accurately reflect how much milk a baby is receiving during breastfeeding.

Myth: If a mother doesn't feel her breasts getting full or leaking milk, she must have a low milk supply.

Fact: Sensations like breast fullness and leaking can vary among individuals and may not always be reliable indicators of milk supply.


Myth: Mothers who have had breast surgery or reduction cannot breastfeed.
Fact: Many women who have had breast surgery or reduction can breastfeed successfully. It depends on the specific surgical procedure and individual circumstances.

 

It's crucial to base decisions about breastfeeding and milk supply on accurate information and consult with healthcare providers or lactation consultants if there are concerns. Breast milk production is a highly adaptive and responsive process, and most mothers can produce enough milk to nourish their babies with the right support and guidance.

Check out the Due Date Club Breastfeeding course to get a comprehensive understanding of breastfeeding and the common challenges we face as new mums (plus amazing advice).