Breastfeeding is recognized as the gold standard for infant nutrition, with compelling evidence for benefits across maternal and infant health.1,2 Despite strong global recommendations for exclusive breastfeeding during the first six months of life, many families encounter challenges that lead to early supplementation or cessation.3 Multiple studies show that the steepest decline in breastfeeding continuation occurs in the first 1–6 weeks postpartum.4–6
Historically, lactation care has included limited prenatal preparation, inconsistent early support and a reactive approach to breastfeeding challenges. However, emerging evidence highlights the benefits of proactive antenatal screening and early postpartum biomarker monitoring, specifically human milk sodium (Na⁺). These strategies help clinicians to identify women at risk of lactation difficulties, and guide timely interventions to keep families on track to meet their breastfeeding goals. This forward thinking approach enables tailored education and lactation care plans, timely referrals to lactation specialists, and objective real-time confirmation of lactation progress.
Why Combine Antenatal Screening with Early Milk Sodium Monitoring?
A recent study by Perrella and colleagues,7 published in the Journal of Midwifery & Women’s Health (2025), examined the prevalence of antenatally identifiable lactation risk factors and their association with breastfeeding outcomes at six to eight weeks postpartum. The findings are compelling: 65.4% of women had at least one antenatal lactation risk factor. The most common were a pre-pregnancy BMI ≥25, gestational diabetes mellitus (GDM), polycystic ovarian syndrome (PCOS), and lack of breast growth during pregnancy.
Of the women with no risk factors, 77.1% were fully breastfeeding at six to eight weeks, considerably higher than the 60.2% of those with one risk factor. The combination of BMI ≥25 and GDM more than doubled the risk of not fully breastfeeding at 6 to 8 weeks postpartum. These results underscore the role of non-modifiable factors (e.g. anatomical variations, metabolic conditions) in influencing lactation outcomes. Identifying these risks early creates an opportunity for targeted support.
Milk sodium concentrations bring a physiologic lens to the early postpartum period. In normal physiology, colostrum sodium concentrations decline rapidly in the first days postpartum as mammary tight junctions close and mature milk production begins. An elevated milk sodium beyond this early window signals delayed secretory activation that is associated with inadequate infant intake. Milk sodium measurement adds an objective, point-of-care metric to complement latch, transfer, and weight assessments, with repeated measures providing real-time feedback on lactation progress.
Understanding the Risk Factor types
Lactation vulnerability is multifactorial. Anatomical factors, such as hypoplasia, prior breast or nipple surgery, and duct‑disrupting piercings, can limit production or transfer from the outset. Minimal or absent breast growth in pregnancy may signal underlying anatomical or metabolic influences and should trigger closer monitoring.7 Endocrine and metabolic factors, particularly BMI ≥25, gestational diabetes mellitus (GDM), polycystic ovary syndrome (PCOS), and thyroid or pituitary disorders, can delay secretory activation and impede sustained milk synthesis, with recent cohort data highlighting BMI and GDM as particularly strong predictors of reduced full breastfeeding at six to eight weeks.7 Finally, psychosocial factors, confidence, intention, and the ability to persist through early difficulties, shape infant feeding decisions in the first weeks.3–6 The thread that connects these categories is practical: structured antenatal screening finds risk early; sodium monitoring then verifies postpartum physiology and supports precision in care.
 | Anatomical - Breast hypoplasia/insufficient glandular tissue
- Prior breast or nipple surgery
- Nipple piercings (especially those damaging ducts)
- No noticeable breast growth in pregnancy
|
 | Endocrine & Metabolic - Elevated pre-pregnancy BMI (≥25)
- GDM, PCOS
- Thyroid or piuitary disorders
|
 | Observed Indicators - Breastfeeding goals
- Understanding family situation and support
- Mental health challenges
|
From Research to Practice: The Antenatal Breastfeeding Screening Tool Linked to Milk-Sodium-Guided Follow-up
To operationalize antenatal risk identification, Dr. Sharon Perrella, Professor Donna Geddes, Dr. Stuart Prosser, and colleagues developed and implemented the Antenatal Breastfeeding Screening Tool (ABST).7 Used during routine mid-pregnancy visits, typically at 24–28 weeks, the tool assesses breastfeeding intentions and history, breast anatomy and changes, metabolic health, and mental health considerations. Risk is stratified into three categories: high risk (red), moderate risk (orange), and no risk (green). High-risk women are recommended to have a breastfeeding class and antenatal lactation consultations with postpartum lactation follow-up, while moderate-risk women are advised to take a breastfeeding class and have follow-up. Those with no identified risk are recommended to attend a breastfeeding class. Implementation sites report that ABST is quick to complete, easy to integrate into standard visits, and well‑accepted by clinicians and families.
Early milk sodium testing (repeated when indicated) verifies that secretory activation is on track, or signals the need to intensify milk removals, refine latch/positioning, and escalate follow‑up.
The Role of Milk Sodium Concentration in Early Lactation Assessment
Milk sodium monitoring offers a practical physiologic window into the timing of secretory activation and the health of the lactating breast, enabling clinicians to move beyond subjective signs toward objective, real‑time decision‑making in the first days and weeks after birth. A variety of thresholds for milk sodium concentrations have been proposed for indicating milk maturity and prediction of future, healthy mammary gland function.8,9 In normal physiology, the relatively high sodium concentrations in colostrum fall rapidly as mammary tight junctions close and mature milk production begins; values ≤16 mmol/L indicate that milk has ‘come in’, whereas persistent elevations above 16 mmol/L in the early postpartum days suggest delayed secretory activation. Readings that fall between 12 and 16 mmol/L are best interpreted as a cautionary zone that warrants closer observation of feeding effectiveness and escalation of milk removals until clear progress is documented. Elevated milk sodium values after milk has ‘come in’ may be a sign of inadequate milk removal with low production, or evolving or subclinical mastitis. Point‑of‑care milk sodium measurement makes this biomarker feasible in routine practice.10 Using a compact ion‑selective electrode meter, just 10 drops of hand‑expressed milk is needed to provide immediate point of care assessment.11,12 Objective milk sodium measures can diverge from maternal perception of milk ‘coming in.’ Serial measurements (rather than a single spot value) provide valuable insights and can be collected at home; these are tightly linked to infant weight trajectories in the first postnatal week.13
The milk sodium concentration values allow clinicians to interpret them against the same physiological thresholds that have been observed in research and clinical pilots. In early implementation work, both clinicians and mothers reported that immediate milk sodium concentration results were acceptable and useful: clinicians found that the number corroborated their clinical impressions and guided timely action, while mothers appreciated the reassurance of “seeing” progress when values fell into the normal range or declined with support. Because milk sodium concentration tracks with closure of mammary gland tight junctions and shifts with inflammatory changes, repeated measures can help guide pumping/latch interventions in suspected low supply, document the transition to mature milk when timing is uncertain, and confirm the onset and resolution of mastitis.
Implications for Healthcare Professionals
For midwives, obstetricians, lactation consultants, and other maternal healthcare providers, the integration of antenatal lactation risk screening with early postpartum milk sodium monitoring represents a meaningful shift from reactive to predictive and preventive lactation support. Rather than waiting for problems to arise, clinicians can identify elevated lactation risk during pregnancy and prepare a proactive, multidisciplinary plan, providing tailored education, assessment and interventions to empower women at risk. In the first weeks after birth, milk sodium measurements offer a rapid and objective confirmation of secretory activation progression or breast inflammation, indicating whether intervention and/or early referral to lactation specialists is needed.
Looking Ahead
Antenatal lactation risk screening provides a valuable clinical tool that can be easily adopted as standard practice in maternity care. At the systems level, embedding the antenatal breastfeeding screening tool alongside point-of-care milk sodium concentration monitoring into clinical protocols and quality‑improvement dashboards enables teams to monitor lactation progress and refine practice over time, ultimately improving breastfeeding continuation. This applies especially to populations with higher risk, such as those with elevated BMI or gestational diabetes. This proactive model aligns with global priorities to reduce maternal and infant morbidity, improve nutrition, and promote health equity.
For now, the message is clear: early identification and intervention can make a measurable difference for mothers and babies.
Take Action Today
Want to learn more about this evidence-based approach and how to implement it in your practice?
Together, we can empower mothers, improve breastfeeding outcomes, and set the foundation for lifelong health.
