EXERCISE IN CRITICAL ANALYSIS. (Lactation Fellowship) When maternal milk production is less than infant caloric need. Eglash 2025

Critical analysis and dissent is vital to the advance of science. Critically analysing a research publication or approach does not devalue that contribution. On the contrary, critique and dissent are signs of valuing, respect, and engagement as we join together to advance the field of breastfeeding and lactation medicine, aligned in our shared value of supporting the very best possible outcomes for breastfeeding women and their families.

Getting started

Dear NDC Lactation Fellowship colleague,

Here, I analyse an Eglash 2025 Commentary published in Breastfeeding Medicine on what to do when maternal breast milk production doesn't meet an infant's caloric needs, available here.

This article makes two important points:

1. Low supply shouldn't be referred to as 'perceived' low supply, since there are valid reasons why women consider their production of milk to be less than their infant's caloric need.

2. Long-term mechanical milk removal may not be in the best interests of the mother, baby, and family ("it is often not in a mother’s best interest to triple feed"), and that formula supplementation in addition to direct breastfeeding may be the best option, depending on context.

However, I'm interested in how medicalised or reductionist lenses become globally authoritative and shape clinical practice, driving the overdiagnosis, overinvestigation, and overtreatment which currently characterise breastfeeding and lactation medicine, sadly also in the context of underdiagnosis and undertreatment of primary aetiologies. You could think of this exercise as a form of textual analysis, in which you reflect upon the extracted statements and the questions, and work out your own position. My reflections are also available, for your consideration.

Kind regards

Pam

Excerpt #1

"Low milk production, for many women, may be a marker of future health problems, including cardiovascular risk."

Questions

Is there any evidence to suggest that a diagnosis of low milk production is a marker of future health problems? What makes a sign or presentation a marker of risk?

Comment

The research literature shows that maternal metabolic health is linked with adverse pregnancy outcomes, suboptimal breastfeeding outcomes, and future cardiovascular risk. But there is no evidence to show that low milk production itself is an independent or direct marker of cardiovascular risk.

In my view the most common reason why maternal milk production fails to meet an infant's caloric need is our health system's failure to identify and manage the foundational causes of inadequate milk removal. Until this has been addressed on a population scale, and taken into account in the research, it is not clinically helpful to claim that low milk supply is associated with future health problems. Unfortunately, an unintended outcome of unsubstantiated claims about future health risk could be further escalatation of pressure to breastfeed, which is known to impact negatively upon maternal mental health.

Excerpt #2

"Oftentimes supplementation of “other” milk is not warranted, but if indicated due to low milk production, the mother needs a workup for diagnosis, treatment, and counseling to optimize milk production." ...

Questions

• Does every mother whose infant requires milk supplementation, in this case in the newborn period, require a workup for diagnosis of low milk supply?

• Does use of the term 'diagnosis' (that is, the differential diagnosis list) include not just intrinsic (metabolic, hormonal) causes, but also extrinsic factors (biomechanical, frequency of milk removal), as identified by Jin et al 2024?

• Could use of the medical terms 'workup' and 'diagnosis' in this context (rather than history/examination/assessment/management) suggest to breastfeeding medicine doctors that their main role is to perform medical investigations? Do breastfeeding medicine doctors need to develop clinical skills for assisting in biomechanics, fit and hold, and breastfeeding-related infant behaviour problems, or should they mostly focus on skills with diagnostics and medical conditions, investigations, pharmaceuticals, and use of aids?

Comment

This mother does however require careful history-taking, examination, assessment, and management, but medical investigations may not yet be indicated (particularly if the woman has received screening antenatal blood tests).

The Merriam Webster online dictionary defines 'work-up' as "an intensive diagnostic study especially for medical purposes"; if workup leans heavily towards medical investigations, then workup may not be a helpful term until foundational interventions have been offered and monitored over time.

Excerpt #3

"Research increasingly suggests that insulin resistance and elevated pre-pregnancy BMI are significant risk factors for delayed or impaired SA [secretory activation]. Primary care physicians and other providers can support breastfeeding by recognizing these risk factors and referring the dyad to a breastfeeding medicine specialist."

Questions

Is referral to a breastfeeding medicine doctor likely to improve outcomes in this case, or will it drive up health system costs due to exacerbation of 'low value care' or overmedicalisation, without impacting upon outcomes and breastfeeding rates? Could a general practitioner or primary care doctor in collaboration with an International Board Certified Lactation Consultant adequately support this woman?

Comment

In my view, every professional who deals with breastfeeding families, including breastfeeding medicine doctors, requires basic skills for the optimising of mother-infant positional stability, minimising conflicting intra-oral vectors of force, and supporting frequent flexible breastfeeds. I have the view that breastfeeding medicine doctors need to develop the most highly advanced clinical skills possible in this area, since these skills are foundational to effective clinical intervention.

The US health system, out of which this article arises, lacks the strength of a primary care system found in countries like Australia. As transdisciplinary generalism teaches us, effective intervention is genuinely holistic, and requires the clinician or doctor to address the multiple factors which interact together in the complex adaptive system of the mother and baby across multiple interacting domains. Fragmentation of clinical breastfeeding support risks worsening already unsustainable health system costs.

Excerpt #4

"Lack of milk transfer can be due to many reasons, such as late preterm birth, sleepy behavior, shallow latching, ankyloglossia, or an occult palatal cleft."

Question

Is this sentence describing primary or secondary aetiologies of suboptimal milk transfer?

Comment

Aetiology refers to the primary or most fundamental causative mechanisms which underlie clinical signs or behaviours or presentations. Late preterm birth, sleepy behavior, shallow latching, and occult palatal cleft aren't primary aetiologies. These presentations or behaviours are only relevant to milk production because they result in suboptimal milk removal, which results from

1. Suboptimal frequency of milk removal, or

2. Biomechanical infant suck challenges. The key extrinsic aetiological factors which result in infant suck challenges are

   • Positional instability or nipple and breast tissue drag - the basic and contextual biomechanical factors which affect infant suck and result in suboptimal milk transfer, due to the associated conflicting intra-oral vectors of mechanical forces. There is a key difference between a medical or reductionist lens which sees infant suck as innately dysfunctional (even in the absence of medically diagnosed neurological abnormality) and the gestalt model which understands infant suck and intra-oral breast tissue volume is contextual and dynamic, dependent upon mechanical factors which the mother is empowered to alter.

   • Conditioned sympathetic nervous system hyperarousal at the breast, which often arises from experiences of positional instability and impacts on frequency of milk removal

   • [Preterm infants may not yet be able to achieve the intra-oral vacuums necessary for adequate milk transfer.]

Excerpt #5

"The best course of action may involve encouraging the mother to express her milk and feed it to the infant until their feeding skills mature or are actively managed."

Question

Is this statement derived from a belief in an infant's innate functional incompetence (suck incompetence)? Is the author suggesting going straight to mechanical milk expression rather applying clinical interventions which address underlying extrinsic primary aetiologies (listed above)? Perhaps this is what the author means by 'actively managed'?

Comment

The author's statement doesn't seem to consider the contextual nature of infant suck and also the steps that should be taken to increase frequency of breastfeeds (a complex management task which includes sensitive education about misinterpretation of infant behaviour and unhelpful cultural feeding pattern norms).

I acknowledge that an intervention which alters the biomechanics of infant suck (which engages context of suck) requires sophisticated clinical intervention, and that there is not a lot of research to guide us. This is, however, a fundamental challenge faced in breastfeeding medicine today, in my view, if we are to improve national and international breastfeeding rates - and respond as effectively as possible to low supply problems.

Excerpt #6

"If low milk production is confirmed, the next step is a differential diagnosis to identify potentially modifiable factors, such as the impact of certain medications (e.g., antihistamines, early postpartum contraception, aripiprazole, decongestants, and cabergoline), thyroid abnormalities, or retained placenta. There are several maternal health factors that negatively impact milk production and are not readily modifiable, such as testosterone-secreting tumors, pituitary insufficiency, or a history of breast surgery or radiation. However, a common but often overlooked cause of low milk production in the early postpartum period is delayed achievement of secretory activation (SA). Research increasingly suggests that insulin resistance and elevated pre-pregnancy BMI are significant risk factors for delayed or impaired SA. Primary care physicians and other providers can support breastfeeding by recognizing these risk factors and referring the dyad to a breastfeeding medicine specialist."

Comment

It's vitally important to identify modifiable factors like medications, thyroid, retained placenta in this case of a larger-bodied woman (obesity) who wishes to breastfeed her baby. However, commonly occurring problems also need to be considered and addressed. There may not be indications for blood test investigation for causes of low supply when it is clear that extrinsic conditions have been suboptimal. If basic biomechanical aetiologies are overlooked as modifiable factors, we are not adequately supporting homeostasis in the complex adaptive system of the breastfeeding mother and baby.

Metabolic disorders are linked with delayed secetory activation, and their prevalence is increasing. But I propose that, in perspective, the most prevalent problems underlying low supply population wide are extrinsic, not intrinsic - despite our increased awareness of the increasing prevalence of maternal metabolic disorders. For instance, in Australia (with one of the better breastfeeding rates globally) a third of newborns receive commercial milk formula in the first week of life; only 39% of women are able to exclusively breastfeed by the end of three months postbirth. As important as antenatal screening, identification, and management of metabolic dysfunctions and other disorders that may impact upon breastfeeding is, these intrinsic causes of low milk supply are much less common than health-system-wide inadequate support of extrinsic factors.

All women at risk from metabolic challenges including obesity also require optimal intervention for support of extrinsic factors which may further compromise secretory activation and milk supply.

NDC is built from the holistic, transdisciplinary generalist lens, which does not try to separate out different parts of a complex problem which needs to be considered as a dynamically interacting whole. Splitting off the breastfeeding medicine doctor's care from skilful focus on the most common aetiologies of low supply risks unnecessary medicalisation and unintended outcomes, and is unlikely to impact upon breastfeeding rates.

Excerpt #7

"If [secretory activation] has already been achieved - confirmed by measuring milk sodium levels - and no identifiable risk factors for low production are found, the mother may be dealing with idiopathic hypogalactia. This condition, though poorly understood, is not uncommon. ... Ideal support for these mothers includes evidence-based methods of optimizing milk production while protecting the mother’s mental health. This would include frequent and thorough milk removal via breastfeeding and/or pumping, along with galactagogues in certain situations."

Question

Does point-of-care measurement of milk sodium levels improve breastfeeding outcomes in comparison with usual clinical indicators? What are the risks of using milk sodium levels to determine secretory activation? Is idiopathic hypogalactia the same as the diagnosis of insufficient glandular tissue? What galactogogues are proposed?

Comment

There is no research to demonstrate that point-of-care measurement of milk sodium levels improves outcomes over careful clinical assessment, although it's validity as a tool for measuring secretory activation is established. Insufficient glandular tissue and idiopathic hypogalactia are diagnoses of exclusion. Until breastfeeding medicine doctors and the health system prioritise the identification and management of the most prevalent determinants of low breast milk supply, we cannot be confident that a hypogalactia is legitimately idiopathic. It may masquerade as a not uncommon diagnosis in the context of widespread health system blind spots.

Excerpt #8

"Ideal support for [idiopathic hypogalactia] includes evidence-based methods of optimizing milk production while protecting the mother’s mental health. This would include frequent and thorough milk removal via breastfeeding and/or pumping, along with galactagogues in certain situations."

Question

What constitutes frequent and thorough milk removal in this case? What is meant by frequent? How is idiopathic hypogalactia or insufficient glandular tissue reliably diagnosed without optimising positional stability, eliminating conflicting intra-oral forces, and educating breastfeeding women about frequent flexible breastfeeds? Would you recommend galactogues as an evidence-based intervention? What kinds and why?

Comment

It could be that thorough milk removal an unhelpful concept since the evidence shows that most milk is transfered in the first two letdowns. The belief that a mother needs to empty or drain the breast can undermine maternal milk production.

I'll pause my analysis there, though you could continue reading and thinking critically about this article yourself if you're keen! You can see I worry that the article offers a medicalised approach which has value in identifying some important causes of low milk production, but which also fails to adequately identify and manage the most foundational and common aetiologies of low milk supply. Low milk supply is a complex presentation affected by dynamic interaction of multiple factors, as the author points out. But if we don't prioritise and discuss skilful intervention for the most fundamental extrinsic aetiologies in our approach to maternal supply that is inadequate for an infant's caloric needs, we may continue to drive up unnecessarily medicalised intervention cascades for breastfeeding problems - which drive up family and health system costs, without improving outcomes.

Reference

Eglash A. Early, unplanned lactation cessation: perspectives from a breastfeeding medicine physician. Breastfeeding Medicine. 2025;20(7):DOI: 10.1089/bfm.2025.0105.

Grattan RE, London SM, Bueno GE. Perceived pressure to breastfeed negatively impacts postpartum mental health outcomes over time. Frontiers of Public Health. 2024;12:https://doi.org/10.3389/fpubh.2024.1357965.

Jin X, Perrella SL, Lai CT, Taylor N, Geddes DT. Causes of low milk supply: the roles of estrogens, progesterone, and related external factors. Advances in Nutrition. 2024;15(1):100129.

Grattan RE, London SM, Bueno GE. Perceived pressure to breastfeed negatively impacts postpartum mental health outcomes over time. Frontiers of Public Health. 2024;12:https://doi.org/10.3389/fpubh.2024.1357965.

Jowell AR, Sarma AA, Gulati M, Michos ED, Vaught AJ, Natarajan P, Powe CE, Honigberg MC. Interventions to mitigate risk of cardiovascular disease after adverse pregnancy outcomes: A review. JAMA Cardiol. 2022 Mar 1;7(3):346-355. doi: 10.1001/jamacardio.2021.4391. Erratum in: JAMA Cardiol. 2023 Aug 1;8(8):797. doi: 10.1001/jamacardio.2023.1778. PMID: 34705020; PMCID: PMC8916981.