Measuring Low Milk Supply: Methods and Implications for Lactation Research and Clinical Practice

Abstract

Background: Low milk supply is a common problem in lactation, yet it is difficult to study and manage due to multifactorial causes and inconsistent measurement across research and clinical practice. Objective: To synthesize current subjective and objective approaches to assessing low milk supply, including scales and survey items, infant weight trajectories and test-weight procedures, milk expression protocols, biomarkers, and device-based metrics. For each method, we appraise validity, feasibility, and potential harms. Key Points: In both research and clinical settings, low milk supply is measured inconsistently and imprecisely. Tools available to assess maternal perception of low milk supply and quantify infant milk intake and production all have limitations. Conclusion: Combining self-report and objective measurements and selecting measurement tools specific to the outcome of interest can help with accurate identification and management of low milk supply.