Introducing Mammoatypical

And Why It Matters

If you have found this site, you might have spent your entire career talking about primary, secondary, and perceived low milk supply—or even the newer, more expansive and intuitive term chronic low milk supply. Or maybe you are brand new to the low milk supply world, suddenly, surprisingly, and unwittingly plunged into it through your own experience. Whether you learned about these designations years ago or just now, the words themselves are important. They help provide context to essential, nuanced discussions about low supply. 

In the hope of continuing to move the low supply conversation forward, we propose a new set of terms:

mammotypical, mammo-typical adj, characterized by normal breast structure or development

mammoatypical, mammo-atypical adj, characterized by atypical breast structure or development that can sometimes limit physiologically normal breastmilk production, with causes such as variations in mammary tissue, hormonal differences, metabolic disease, nipple morphology (e.g., inverted, flat, bifurcated), or breast surgeries or procedures

We started using these terms because we needed them in our support group, since no other single words existed to characterize our collective identity and experience—as well as the norm that we are constantly comparing ourselves to, often to our detriment. In our mission statement we discuss this unavoidable reality: we are operating in a system that is ultimately not made for people with primary or chronic low supply, no matter how skilled or empathetic the perinatal providers and professionals who care for us are. So doesn’t it follow that, as those practitioners, we should be asking ourselves a very important question: which populations do we have a responsibility to serve? And whatever the good intentions, is it acceptable to do what is best for the mammotypical community at the expense of the mammoatypical and their babies? We believe that is the status quo but also something that should change. It doesn’t mean turning the system on its head and routinely offering supplementation to all new parents, or saying that formula and breastmilk are equally beneficial from a medical perspective; we are not advocating for that in any way. But by adjusting the protocols of how we educate about and screen for risk factors of low supply, it may be possible to protect each population without harming the other.

Why mammotypical-focused care is important

There is true value in promoting practices that will lead to more babies getting more human milk (Victora et al., 2016), but many families do not meet their breastfeeding goals. In one study of first-time mothers, 70 percent intended to exclusively breastfeed and only 50 percent were still doing so after one week (Declercq et al., 2009). Perceived low milk supply (PIMS) is often cited as a major factor in the early discontinuation of breastfeeding; a systematic review of rates and factors of PIMS found that it was given as the reason for stopping breastfeeding by 50 percent of subjects (Huang et al., 2022). Further, PIMS is associated with limited breastfeeding knowledge and misinterpretation of normal infant behavior (Huang et al., 2022), along with lower maternal breastfeeding self-efficacy (Galipeau et al., 2018; Huang et al., 2022; Sandhi et al., 2020). Interventions geared toward supporting exclusive breastfeeding are critical because many parents introduce supplementation without medical necessity during the first days postpartum, which is associated with a lower likelihood of continued breastfeeding (Chantry et al., 2014). Another study indicated that there could possibly be a causal link between in-hospital formula supplementation and early discontinuation of breastfeeding (Whipps et al., 2021). The focus on empowerment and confidence in lactation education and in the early postpartum period recognizes that it’s natural for new parents to (usually mistakenly) believe that the baby is not getting enough and then adjust their behavior accordingly. The goal of discouraging such behavior is to allow for more babies and lactating parents to experience the benefits of exclusive breastfeeding, and for more families to meet their feeding goals. 

Why protecting the milk supply of the mammotypical population should not be done at the expense of the mammoatypical

There are many benefits to exclusive breastfeeding both for the parent and child (Victora et al., 2016), when it is physiologically possible. So education to prevent unnecessary supplementation in the first days of life is reasonable in cases where exclusive breastfeeding is desired. However, for people with primary low milk supply, the mere introduction of unnecessary supplementation is a nonissue because by definition these babies require supplementation in the form of donor milk or formula. (Of course, the amount of supplementation they will ultimately need does still typically depend on breastfeeding management in the early days.) Parents with primary low supply have reported not having received adequate education and medical advice for their condition (Whelan et al., 2025), and we also see this with members of our support group. In many cases, breastfeeding guidance is generalized and targeted to the large percentage of people who are capable of making a full supply with proper breastfeeding management. This seems only natural, and perhaps such a strategy is better for more babies overall. But for a small but significant subset of infants, excessive weight loss is associated with neonatal readmissions, and the authors of one paper suggest that this risk may be reduced with improved clinical management (Flaherman et al., 2018). When it comes to families at risk of primary low milk supply, the conclusion of that paper makes a lot of sense since our babies will be underfed if they do not eventually receive supplementation. 

To put all this another way: it is true that many parents introduce nonmedically indicated supplementation when their goal is to exclusively breastfeed. But it is also true that too many people in the low supply community have a shared lived experience: we were told that despite clinically significant early weightloss, our babies didn’t need supplementation—even past those first days when babies are expected to lose weight—only to find out later that we have primary low milk supply and were never capable of producing the amount of milk our babies needed to thrive. We commonly hear variations of this story in our support group and other spaces for people with primary or chronic low milk supply. It doesn’t happen to all of us, but it happens. It’s also presumably the reason Baby Friendly USA published this article. Both populations can benefit from unbiased, complete education on indications the baby is getting enough milk as well as the warning signs of inadequate intake; articles like this one from La Leche League empower parents by equipping them with this information.

The fear of unnecessary supplementation and its consequences should not prevent our community from getting medical advice that is tailored to our bodies and that can have a profound impact on our babies’ health and our postpartum experience. The problem is that we don’t actually know we have primary or chronic low supply until we have followed breastfeeding best practices for the first weeks of our babies’ lives. In light of all this, we propose two simple changes that we believe can protect the mammotypical population and their babies while also ensuring appropriate care for those of us who are at risk of not being able to make a full milk supply:

Teach Everyone

The possibility of and risks for primary low supply—as well as common reasons for delayed onset of copious milk production—should always be discussed in breastfeeding education, particularly prenatally. Coverage of this topic can be brief, but it should exist. Having this information can empower those at risk of low supply to mentally and physically prepare. It causes harm to make us feel that everyone who tries hard enough can produce a full milk supply, but that is so often what members of our community are taught.

Screen Everyone

All pregnant patients deserve to be screened for the risk factors of primary or chronic low milk supply and delayed lactogenesis II, and when possible, high-risk patients should receive personalized prenatal lactation support from an IBCLC, breastfeeding medicine provider, or breastfeeding-savvy clinician. Communication with hospital staff and pediatricians when these risk factors are present may help encourage extra precautions in monitoring weight loss and choosing if and when to introduce supplementation. This is not a new concept, and in 2021 members of the Low Milk Supply Research Consortium also called for a similar change to perinatal care (Shere et al., 2021). More recently, the Academy of Breastfeeding Medicine (ABM) wrote guidance to this effect in its position statement on overfeeding and underfeeding (Feldman-Winter et. al, 2024), which we hope will become canon for all clinicians who work with breast/chestfeeding dyads. (If that’s you, please read ABM’s statement and don’t miss the table about causes of low supply at the end.) Despite these recommendations, members of our community, along with our babies, are still suffering in a system that so often does not acknowledge the existence of our condition. We are making progress, but we’re not there yet.

Why is all this important? Providers and lactation professionals alike have an ethical responsibility to serve not only mammotypical parents and their babies, but also the mammoatypical population—of course with consideration for the public health implications of promulgating an often overlooked concept in lactation education: that the common teaching that everyone can breastfeed is mostly true but in fact ultimately a myth.

 

References

Victora, C. G., Bahl, R., Barros, A. J. D., França, G. V. A., Horton, S., Krasevec, J., Murch, S., Sankar, M. J., Walker, N., Rollins, N. C., & Lancet Breastfeeding Series Group. (2016). Breastfeeding in the 21st century: Epidemiology, mechanisms, and lifelong effect. The Lancet, 387(10017), 475–490. https://doi.org/10.1016/S0140-6736(15)01024-7

Declercq, E., Labbok, M. H., Sakala, C., & O’Hara, M. (2009). Hospital practices and women’s likelihood of fulfilling their intention to exclusively breastfeed. American Journal of Public Health, 99(5), 929–935. https://doi.org/10.2105/AJPH.2008.135236

Huang, X., Liu, Y., Yu, C., & Zeng, L. (2022). The rates and factors of perceived insufficient milk supply: A systematic review. Maternal & Child Nutrition, 18(1), e13255. https://doi.org/10.1111/mcn.13255

Galipeau, R., Baillot, A., Trottier, A., & Lemire, L. (2018). Effectiveness of interventions on breastfeeding self‑efficacy and perceived insufficient milk supply: A systematic review and meta‑analysis. Maternal & Child Nutrition, 14(3), e12607. https://doi.org/10.1111/mcn.12607

Sandhi, A., Lee, G. T., Chipojola, R., Hasanul Huda, M., & Kuo, S.-Y. (2020). The relationship between perceived milk supply and exclusive breastfeeding during the first six months postpartum: A cross-sectional study. International Breastfeeding Journal, 15(1), 65. https://doi.org/10.1186/s13006-020-00310-y

Chantry, C. J., Dewey, K. G., Peerson, J. M., Wagner, E. A., & Nommsen-Rivers, L. A. (2014). In-hospital formula use increases early breastfeeding cessation among first-time mothers intending to exclusively breastfeed. The Journal of Pediatrics, 164(6), 1339–45.e5. https://doi.org/10.1016/j.jpeds.2013.12.035

Whipps, M. D. M., Yoshikawa, H., Demirci, J. R., & Hill, J. (2021). Estimating the impact of in‑hospital infant formula supplementation on breastfeeding success. Breastfeeding Medicine, 16(7), 530–538. https://doi.org/10.1089/bfm.2020.0194

Whelan, C., O’Brien, D., & Hyde, A. (2025). Breastfeeding with primary low milk supply: A phenomenological exploration of mothers’ lived experiences of postnatal breastfeeding support. International Breastfeeding Journal, 20(7). https://doi.org/10.1186/s13006-025-00699-4

Flaherman, V. J., Schaefer, E. W., Kuzniewicz, M. W., Li, S. X., Walsh, E. M., & Paul, I. M. (2018). Health care utilization in the first month after birth and its relationship to newborn weight loss and method of feeding. Academic Pediatrics, 18(6), 677–684. https://doi.org/10.1016/j.acap.2017.11.005

Shere, H., Weijer, L., Dashnow, H., Moreno, L. E., Foxworthy Scott, S., & Baker, H. (2021). Chronic lactation insufficiency is a public health issue: Commentary on “We need patient-centered research in breastfeeding medicine” by Stuebe. Breastfeeding Medicine, 16(12), 933–934. https://doi.org/10.1089/bfm.2021.0202

Feldman‑Winter, L., Ware, J., Schreck, P., Kellams, A., Rosen‑Carole, C., & Rouw, E. (2024). ABM position statement: Recommendation for exclusive breastfeeding — Avoidance of underfeeding and overfeeding. Academy of Breastfeeding Medicine. https://www.bfmed.org/assets/DOCUMENTS/PositionStatements/SupplmentationStatement.pdf