What Counts as Low Milk Supply? Measurement, Biomarkers, and What's Next with Dr. Katie Kivlighan

Low milk supply might be the most common concern we field—and one of the hardest things in lactation to actually measure. In this episode I sit down with researcher Dr. Katie Kivlighan to separate what we can quantify from what we're guessing at, and to look at the tools and technologies that are about to change how we assess it. ## Episode Summary "Low milk supply" gets used as a catch-all, but it isn't one thing—and treating it like one thing is part of why families get the wrong support. Dr. Katie Kivlighan, co-author of *Measuring Low Milk Supply: Methods and Implications for Lactation Research and Clinical Practice* (Journal of Human Lactation, 2026), joins me to walk through the difference between primary, secondary, and perceived low supply, and why our measurement methods have never fully caught up with the problem. We get into what the evidence actually supports right now: test weights, milk transfer, and biomarkers like sodium and conductance—plus the emerging technologies (bioimpedance, at-home milk sodium testing) that could give us objective data we've never had at the bedside. We also talk honestly about the flip side: how devices and social media can feed parental anxiety, how normal infant behavior gets misread as a supply problem, and where clinical judgment still has to lead. If you support families navigating supply concerns, this one is about sharpening how you assess, how you reassure, and how you decide when a number actually matters. ## What You'll Learn - The real difference between primary, secondary, and perceived low milk supply—and why the distinction changes your entire plan of care - Why milk supply is so hard to measure accurately, and what that means for how we interpret research - What biomarkers like sodium and conductance can (and can't) tell you about secretory activation - Where bioimpedance and at-home milk sodium testing are headed, and how to think about them before they land in your practice - The infant behaviors that get misread as low supply—so you can spot them and reframe them for families - How feeding technology and social media are driving parental anxiety, and your role in cutting through the noise - Why milk intake "standards" deserve a second look, and how normal supply variability fits in - When to bring in a breastfeeding medicine provider, and how that collaboration strengthens care - How to hold objective tools and clinical judgment together instead of letting one override the other ## Chapters - 00:00 — Introduction and Dr. Kivlighan's research background - 05:53 — Low milk supply: types and challenges - 08:12 — The role of perception in supply concerns - 10:31 — Evaluating milk supply: tools and techniques - 13:11 — Common misinterpretations of infant behavior - 15:46 — How technology feeds parental anxiety - 18:16 — Collaborating with lactation professionals - 20:40 — Reassessing milk intake standards - 26:39 — Understanding milk supply variability - 27:20 — Emerging technologies in lactation - 32:23 — Bioimpedance and milk measurement innovations - 34:58 — Addressing delayed secretory activation - 41:27 — The case for comprehensive lactation support - 43:02 — Closing thoughts ## Resources Mentioned - Kivlighan, K. T., & Demirci, J. R. (2026). Measuring low milk supply: Methods and implications for lactation research and clinical practice. *Journal of Human Lactation, 42*(1), 126–134. https://doi.org/10.1177/08903344261426744 - Dr. Katie Kivlighan: - Faculty page - Research profile ## Your Next Steps - Learn with Me: https://margaretsalty.com/courses - Read the Blog: https://margaretsalty.com/blog - Email Me: hello@margaretsalty.com - LinkedIn: https://www.linkedin.com/in/margaret-salty-drph-ibclc-ches-0133451b/ - Instagram: https://www.instagram.com/margaretsalty/ - Facebook: https://www.facebook.com/profile.php?id=61550829710885 *Music: The Magnifiers — "My Time Traveling Machine"*https://open.spotify.com/track/5Q7WMVIaE9Kos3eMHUvvow?si=e38d0c090ff94cab