Maximizing Milk Removal: Why Multiple Letdowns Matter
TLDR: Achieving multiple milk ejections (letdowns) during breastfeeding or pumping sessions is crucial for optimal milk removal, better milk supply maintenance, and accessing the full spectrum of breast milk. Most mothers naturally experience 2-3 letdowns per session, and understanding how to facilitate these can significantly improve pumping efficiency and overall lactation success.
Understanding the Milk Ejection Reflex & The Anatomy of Milk Storage
The milk ejection reflex, commonly called "letdown," is a sophisticated hormonal process that makes breastfeeding possible. When your baby suckles or when you begin pumping, sensory impulses travel from your nipple to your brain, triggering the release of two critical hormones: prolactin and oxytocin.
Prolactin stimulates milk production in the alveoli, while oxytocin causes the myoepithelial cells surrounding the alveoli to contract, pushing milk through the milk ducts toward the nipple. This coordinated response ensures that milk stored in your breast becomes available to your baby or pump.
Understanding breast anatomy helps explain why multiple letdowns are so important. The breast stores most milk in the alveolar region. The majority of milk in the human mammary gland is stored in the alveolar region and requires active expulsion for successful lactation, such that the absence of the milk ejection reflex results in very little milk removed from the breast.
This means that without active milk ejection, only about 20-30% of available milk can be accessed through suction alone. The rest requires oxytocin-triggered contractions to push it through the milk ducts. If you’re looking for more details to understand your breast anatomy, I’ve got you covered! This Booby Break Down blog will go much deeper into the anatomy!
Why Multiple Letdowns Are Essential
1. Fully Emptying The Breast
Having several let-downs helps to empty your breast and keep your baby eating on the breast with a constant milk flow. Research shows that babies typically remove only 63-72% of available milk during feeding, but this doesn't mean the breast is empty—it means the baby stops feeding due to satiety, not milk depletion.
For pumping mothers, achieving multiple letdowns can mean the difference between a 1-ounce output and a 3-5 ounce output from the same session. If I pumped 1 oz in my first letdown, I might get another 1.5 oz in my second letdown, and .75 oz in my third. That's an extra 2.25 oz than if I had thought my breasts were empty, and just stopped pumping after the first letdown.
2. Accessing Different Milk Compositions
The fat content of breast milk increases progressively throughout a feeding session. Early milk contains more lactose and less fat, while later milk is rich in calories and essential fatty acids. Multiple letdowns ensure babies and pumping mothers access this complete nutritional spectrum.
3. Maintaining Long-Term Milk Supply
The principle of supply and demand governs milk production. More complete breast emptying through multiple letdowns signals your body to maintain or increase milk production. This is particularly crucial for exclusively pumping mothers who rely entirely on mechanical stimulation to maintain their supply. If you need to understand how to keep your milk supply demand up then read up on that HERE.
4. Preventing Common Breastfeeding Problems
Incomplete milk removal can lead to:
Engorgement
Blocked ducts
Mastitis
Decreased milk supply over time
The Bottom Line:
Your body is designed for this remarkable process. With knowledge, patience, and proper support, you can master the art of multiple letdowns and enjoy the full benefits of optimal milk removal for both immediate feeding success and long-term lactation goals. If you find yourself needing help to achieve your goals, don’t hesitate to book so we can get you on your way to achieving success!
Resources:
World Health Organization. (2009). The physiological basis of breastfeeding. In Infant and Young Child Feeding: Model Chapter for Textbooks for Medical Students and Allied Health Professionals. Geneva: World Health Organization. Available from: https://www.ncbi.nlm.nih.gov/books/NBK148970/
Australian Breastfeeding Association. (2024). The let-down reflex and your milk flow. Available at: https://www.breastfeeding.asn.au/resources/let-down-reflex-and-your-milk-flow
Pregnancy Birth and Baby. (2024). Let-down reflex. Australian Government Department of Health. Available at: https://www.pregnancybirthbaby.org.au/let-down-reflex
Multiple Letdowns and Milk Removal Efficiency
Wambach, K., & Riordan, J. (2016). Breastfeeding and human lactation. Jones & Bartlett Learning.
Prime, D.K., et al. (2019). Comparison of maternal milk ejection characteristics during pumping using infant-derived and 2-phase vacuum patterns. International Breastfeeding Journal, 14, 45. https://internationalbreastfeedingjournal.biomedcentral.com/articles/10.1186/s13006-019-0237-6
Kent, J.C., et al. (2012). Principles for maintaining or increasing breast milk production. Journal of Obstetric, Gynecologic & Neonatal Nursing, 41(1), 114-121. https://www.jognn.org/article/S0884-2175(15)31026-1/fulltext
Breast Anatomy and Milk Storage
Wagner, C.L., & Hollis, B.W. (2018). Milk ejection - an overview. In Best Practice & Research Clinical Endocrinology & Metabolism. Available at: https://www.sciencedirect.com/topics/medicine-and-dentistry/milk-ejection
Ramsay, D.T., et al. (2005). Anatomy of the lactating human breast redefined with ultrasound imaging. Journal of Anatomy, 206(6), 525-534.
Fat Content and Milk Composition Changes
Mizuno, K., et al. (2009). Is increased fat content of hindmilk due to the size or the number of milk fat globules? International Breastfeeding Journal, 4, 7. https://internationalbreastfeedingjournal.biomedcentral.com/articles/10.1186/1746-4358-4-7
Andreas, N.J., et al. (2017). Peptides released from foremilk and hindmilk proteins by breast milk proteases are highly similar. Nutrients, 9(2), 136. https://pmc.ncbi.nlm.nih.gov/articles/PMC5673630/
KellyMom. (2023). Foremilk and hindmilk – what does this mean? Available at: https://kellymom.com/bf/got-milk/basics/foremilk-hindmilk/
Supply and Demand Physiology
Ip, S., et al. (2009). The risks of not breastfeeding for mothers and infants. Pediatrics, 125(5), e1048-e1059. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2812877/
Neville, M.C., et al. (2016). Biological underpinnings of breastfeeding challenges: the role of genetics, diet, and environment on lactation physiology. American Journal of Physiology-Endocrinology and Metabolism, 311(2), E405-E422. https://pmc.ncbi.nlm.nih.gov/articles/PMC5005964/