Do certain (macroscopic) maternal anatomic variations cause breastfeeding difficulties?

Some studies have linked certain (poorly defined) maternal anatomic variations with breastfeeding problems

Certain poorly defined anatomic variations have been shown in some preliminary studies to link with breastfeeding problems, including nipple pain.

• A 2009 Iranian study showed that 50 newborns to mothers who presented with a flat nipple, inverted nipple, large breast and/or large nipple did not increase in mean weight (or had a mean decrease in weight) by day seven compared to 50 newborns whose mothers did not have these breast variations.

• A 2013 Thai study showed that nipple lengths of less than 7 mm were less likely to initiate breastfeeding in the first 24 hours. Smaller breast size and longer nipple lengths were associated with longer breastfeeding durations.

• A 2017 Brazilian systematic review into factors associated with nipple pain found a link between nipple pain and "semi-protruding and/or malformed nipples", in the absence of any further clarifying definitions. (The term "malformed nipple"s does not refer to normal anatomic variation, but to congenital abnormality.)

• A 2020 study of 119 participants at a Californian breastfeeding centre showed that various combinations of wider, longer nipples and denser areolas were associated with difficulty latching, sore nipples, low milk supply and slow infant weight gain.

A breastfeeding atlas which is commonly recommended as a resource for lactation consultants speculates that larger breasts, shorter and wider nipples, and denser areolas (determined by gentle squeezing at base of nipple to test elasticity) disproportionately cause early breastfeeding challenges. This claim is not based on research, but upon the author's clinical experience. For example, we don't know the approach to fit and hold typically used by the author when working with breastfeeding women.

This research listed above and the clinical anecdote in the atlas emphasise just how important it is for breastfeeding women to have education about the strategies which will help to eliminate breast tissue drag and have the baby draw up as much breast tissue as possible into his mouth, regardless of anatomic variability.

What is useful for a clinician to know about the link between larger-bodied women and breastfeeding difficulty?

It is clear from the research that larger bodied women are at increased risk of breastfeeding difficulty. However, how to make sense of (or interpret) this data is less clear. The relationship between breastfeeding and being larger bodied is likely to be complex. For example, I propose that the impact of being larger-bodied upon fit and hold is not controlled for.

This is how I make sense of the association between being larger bodied and increased risk of breastfeeding difficulty.

• Fit and hold and effective management of the special challenges raised by being a larger bodied woman or a woman with generous breasts remains a serious health system blind spot. Would the negative outcomes be as significant if this blind spot was addressed?

• Being a larger bodied pre-pubescent child or adolescent alters pathways of mammary gland development and appears to affect both the maturity of and volumes of glandular tissue, which may impact upon timing of secretory activation and volumes of milk production.

The links between larger-bodied women and breastfeeding difficulties need to be held in perspective.

• You can watch a presentation by endocrinologist-researcher Dr Katie Rassie updating health professionals on the links between larger-bodied women and breastfeeding difficulty here.

• You can read about holding the association between diabetes and poorer breastfeeding outcomes in perspective here.

It is possible that the psychological effects of pathologising normal anatomic variation is a more powerful cause of breastfeeding distress and failure than the variations themselves?

I propose that pathologising anatomic diversity and blaming the mother or baby’s otherwise healthy body is a compensation for our lack of effective tools for clinical breastfeeding support, in particular with respect to fit and hold. This is no individual practitioner’s fault, but arises out of our history of a relative a lack of investment in clinical breastfeeding and lactation research. For example

• Healthcare challenges specifically relevant to women's bodies have not been prioritised in research.

• Breastfeeding problems have been seen as 'soft' concerns. (At least the woman and her baby are alive and well, doctors have often said!)

• There are powerful ideological forces at work within breastfeeding and lactation advocacy networks which aim, through social media use and active exclusion of certain new work from networks and conferences, to silence the same researchers and clinicians who are most likely to contest dominant, pathologising paradigms in this field.

It is possible that the psychological effects of pathologising normal anatomic variation (and the failure to look for other solutions) is a more powerful cause of breastfeeding distress and failure to explore potentially helpful interventions, than the effect of the anatomic variations themselves. This effect would need to be controlled for in randomised controlled trials.

Selected references

Dias JS, Vieira TDO, Vierira GO. Factors associated to nipple trauma in lactation period: a systematic review. Revista Brasileira de Saude Materno Infantil. 2017;17(1):27-42.

Hendry P. Anatomical variation exploring diversity causes and clinical relevance. International Journal of Anatomic Variations. 2024;17(6):601-602.

Mizrachi B. Unraveling the spectrum of variation in human anatomy insights from genetics, development, and evolution. International Journal of Anatomic Variations. 2024;17(2):520-521.

Puapornpong P, Paritakul P, Suksamarnwong, Srisuwan S, Ketsuwan S. Nipple pain incidence, the predisposing factors, the recovery period after care management, and the exclusive breastfeeding outcome. Breastfeeding Medicine. 2017;12:169-173.

Vazirinejad R, Darakhshan S, Esmaeili A, Hadadian S. The effect of maternal breast variations on neonatal weight gain in the first seven days of life. International Breastfeeding Journal. 2009;4(13).

Ventura AK, Lore B, Mireles O. Associations between variations in breast anatomy and early breastfeeding challenges. Journal of Human Lactation. 2020:doi:10.117/10890334420931397.

Wilson-clay and Hoover 2017. The breastfeeding atlas (6th edition), LactNews Press.