Many mothers feel unsure or even discouraged in the early days, worried whether their milk is “coming in” and that something is wrong. 

The Breastfeeding Medicine Podcast, hosted by two physicians who are also IBCLCs and experts in breastfeeding care, recently talked about our JMIR-published study in a way that helps explain this early stage of milk production more clearly and with a scientific and practical perspectives.

Listen to Breastfeeding Medicine Podcast #106, at IABLE, by Dr. Anne Eglash MD, IBCLC, FABM and Dr. Karen Bodnar MD, IBCLC, FABM  

Understanding How Milk “Comes In”

The hosts began by explaining that many people are told to watch for their breasts feeling fuller or heavier as a sign that milk has arrived. But as they shared, this isn’t always reliable. Before drilling to the JMIR research, the hosts explain the biological process that is happening inside the breasts in this transition towards milk producing tissue, and describes the milk transition occurs in simple terms: early colostrum naturally has more sodium electrolyte and as the milk-making system becomes more organized, the sodium level drops, showing that milk is maturing. They highlighted that our research uses this change in milk electrolytes to measure milk progress scientifically, rather than relying on how fullness feels.

Seeing Milk Progress Day by Day

The podcast discussed our JMIR research, which used a small milk-sensing tool to look at how this process changes over time. Instead of offering a binary yes/no answer, the research expressed milk progress on a continuous maturity scale, which the podcast hosts described as a gradual progression.

One of the hosts explained it this way: “It was like you’re 20% there, you’re 40% there, you’re 60% there… close to having your milk fully come in.”

They talked about how some parents reached high maturity levels during the first week after birth, while others showed much slower patterns that continued into the second and third weeks or beyond. The slower patterns, as the host explains, are connected to situations where mothers were reported to have low milk production or breastfeeding problems.

They discussed how this kind of day-by-day information could help make sense of situations where milk seems delayed. Rather than depending on feelings of fullness or on pumping amounts, the milk electrolyte-based maturation pattern offered a clearer view of how milk production was unfolding.

 

Why This Matters When Milk Seems Slow

The podcast hosts spoke openly about how challenging early milk concerns can be, both for families and for clinicians. They described real situations from their own practice where parents struggled for days, and how watching the maturation pattern could help identify whether milk was still in the early stages of development. They shared that looking at the milk’s maturity, and reflecting status within this continuing progression, could help make sense of these situations.

They also discussed how maturation is not just a static stage, but something that can change with breast stimulating frequency. One of the hosts explained that nursing or pumping very often keeps prolactin levels high, leading to earlier progress in milk production. When breastfeeding or pumping is infrequent, electrolyte levels can “stay high for a while,” showing that maturation is moving more slowly. This means the pattern can respond to what a parent is doing.

The hosts also reflected on how this day-to-day picture could help clinicians understand whether someone is making progress or whether something may be blocking or delaying milk production. They described situations where, if sodium electrolyte stayed high on a later day [MM% delayed], it could help explain that the body had not yet completed secretory activation process. If sodium electrolyte was low [MM% advanced] but volumes were small, it could suggest a different situation, such as insufficient glandular tissue. These examples came from their own clinical experiences, appreciating the potential value of such milk sensing data in breastfeeding case navigation.

Their reflections stayed grounded in compassion, acknowledging how emotional and confusing those early days can be. One host captured the emotional importance of such differentiation and reflection to the mothers: “People want to know, right? They want to know where they’re at.”

Understanding “Milk Maturation” for Yourself

The podcast’s host explains the Milk Maturation percentage (MM%) developed in this study into simple terms. Milk Maturation is a way of showing how far along your milk is in its natural transition from colostrum toward mature milk. Instead of saying milk has or hasn’t “come in,” it shows the degree of that progression, and follow it till full maturity.

Some parents progress quickly, and others progress more slowly, and this is indicative of breastfeeding challenges and milk supply progress. if the Milk Maturation progress seems slower than expected, it can be an early signal to reach out, ask questions, and work more closely with your lactation consultant. For example, they may suggest more frequent breast stimulation, checking for any obstacles, or adjusting your plan together. 

Seeing this progression, and tracking day-by-day information can help mothers and breastfeeding professionals understand their own situation and follow how things are changing over time, adding some clarity to the overwhelming early lactation period.

Listen to Breastfeeding Medicine Podcast #106, at IABLE, by Dr. Anne Eglash MD, IBCLC, FABM and Dr. Karen Bodnar MD, IBCLC, FABM