Who is milk sharing online?

Truth be told, I’m not a huge fan of surveys. I think they are clunky – so much is lost in the process of reducing social processes to discrete, measurable variables. Sometimes, though, there’s just no getting around the fact that you need to do a survey.

Surveys can help us describe population characteristics. They can be used to test hypotheses. They can help us detect patterns that may be unexpected or hidden. When used with interviews and ethnographic research, surveys can be a kind of compass, pointing us in new and exciting directions. Surveys have their place.

And so, to kickoff my milk sharing project I did one. I designed an online tool that would help  me answer some basic who, what, where, when, why and how questions about milk sharing.

Survey says!

My brilliant colleague, Kirstie Doehler, and I analyzed a handful of the survey items and then wrote a paper. It was published online in October 2014 in the journal Social Science & Medicine, and is the first to describe who is milk sharing in the U.S.

Here is an infographic that summarizes our key findings (click on the infographic to view/share the spiffy online interactive presentation!):

SSM 2014 piktochart-3

Basic characteristics

People who are already familiar with milk sharing will not find these results particularly earth shattering. I mean, it makes total sense that mothers who are sharing their breast milk would meet recommended breastfeeding guidelines. It also makes sense that recipients would be able to do the same, since maximizing breast milk feeding is sorta the whole point of milk sharing.

In the U.S., mothers who breastfeed as recommended tend to be relatively privileged socially: they are well-educated, middle-income, mostly white women with access to lots of breastfeeding support (Fein et al. 2008; McCarter-Spaulding 2008). But, mothers who are milk sharing are not exactly your ordinary, average, everyday sane psycho supergoddess breastfeeding mothers.

[cue Liz Phair music]:


These are women who place an extraordinarily high value on breastfeeding and breast milk (Akre, Gribble, & Minchin 2011; Gribble & Hausman 2012; Gribble 2013, 2014a, 2014b, 2014c; Perrin et al. 2014; Cassidy 2012a, 2012b; Thorley 2009, 2012).

Social constraints and breast milk supply and demand

It turns out that you can’t get around the political economy of breastfeeding, either, when talking about differences in breast milk production, even when your study population is a group of rather “homogenous, middle-income women.” The combined donor-recipient breastfeeding rates in this population are high. But, when we looked at differences between donors and recipients, we found that social constraints, pre-term birth, C-section birth, and low pediatrician support disproportionately affected lower-middle income mothers, who were more likely to have low milk supply. I guess the middle-class isn’t as homogenous one might expect.

Milk sharing and recipients’ infant feeding strategies

I think sometimes people wonder if milk sharing makes recipient mothers somehow lazy to breastfeed or leads them to give up on breastfeeding altogether. If they can “get it for free,” then why bother with putting baby to breast or continuing to pump?

Our study shows that most milk sharing recipients, who are also breastfeeding mothers, continued to breastfeed or express their milk even when they were milk sharing. Understanding how and why these recipient mothers manage to have really high breastfeeding/breast milk feeding rates is  a question worthy of further exploration using qualitative and ethnographic approaches.

Milk sharing and donors’ lactation trajectories

It’s also fascinating that the mothers who donate don’t just meet recommended breastfeeding guidelines, they exceed them…significantly. This begs the question: is there something about milk sharing that inspires donors to breastfeed or express milk longer than they would if they were not donating? We didn’t assess this in our survey, but preliminary interview data suggests this might be the case, especially for donors who express milk for one (or a few) recipient babies for a sustained period of time, or who pump already knowing that they hope to share their milk.

These findings are really exciting to me as a medical anthropologist, because it provides this fascinating example of how social connectedness influences human biology. Technology is obviously also an important factor to consider (I’ll save that thought for another post).

Again, I think these milk sharing mothers are unique, but there is value in understanding why they do what they do. How might we draw lessons from milk sharing that could perhaps lead to more donations to non-profit human milk banks? What can we learn about the social context of milk sharing that might be used to increase breastfeeding rates in other populations, where breastfeeding is the exception, not the norm?

Social context is important, but it’s not everything

We only look at social factors in this paper – and we used factors that are well established in the literature to have some influence on breastfeeding outcomes. However, breastfeeding is biocultural – social context and biology collide to produce variations in milk supply, and social factors influence biology differently depending on various axes of inequality and identity. We don’t fully understand why some women make lots of milk and others make so little, but I can say with confidence that social context is only one piece of a very complicated puzzle.

Paying attention to silences in the data

Before I sign off, it’s important to note that there are huge gaps in our survey data, namely for women of color and groups other than breastfeeding mothers who are milk sharing (like adoptive parents, grandparents, foster parents, LGBT*Q parents, and parents of surrogate babies). In my mind, these silences are where the incredible richness, diversity, and complexity of milk sharing lie. As we wrote in our paper:

The pathways that lead to breastfeeding success or cessation are extremely varied and multifaceted. Not all breastfeeding practices follow a linear trajectory, and the patterns observed in our data may not apply to all families who choose milk sharing as an infant feeding choice…it is important to note that these data are merely a cross-sectional snapshot of a dynamic, rapidly evolving practice, and they do not necessarily capture the full range of factors or experiences that propel families into milk sharing.

All of these unanswered questions just mean new opportunities for further ethnographic inquiry!



Akre, J.E., Gribble, K.D., Minchin, M., 2011. Milk sharing: from private practice to public pursuit. Int. Breastfeed. J. 6, 13.

Cassidy, T.M., 2012a. Making milky matches: globalization, maternal trust, and lactivistonline networking. J. Mother. Initiative 3, 226240.

Cassidy, T.M., 2012b. Mothers, milk, and money: maternal corporeal generosity, social psychological trust, and value in human milk exchange. J. Mother. Initiative 3, 96111.

Fein, S.B., Labiner-Wolfe, J., Shealy, K.R., Li, R., Chen, J., Grummer-Strawn, L.M., 2008. Infant feeding practices study II: study methods. Pediatrics 122, S28S35.

Gribble, K.D., 2013. Peer-to-peer milk donors’ and recipients’ experiences and perceptions of donor milk banks. J. Obstet. Gynecol. Neonatal Nurs. 42, 451461.

Gribble, K.D., 2014a. Perception and management of risk in internet-based peer-topeer milk-sharing. Early Child Dev. Care 184, 8498.

Gribble, K.D., 2014b. I’m happy to be able to help:why women donate milk to a peer via internet-based milk sharing networks. Breastfeed. Med. 9, 251256.

Gribble, K.D., 2014c. A better alternative: why women use peer-to-peer shared milk. Breastfeed. Rev. 22, 1121.

Gribble, K.D., Hausman, B.L., 2012. Milk sharing and formula feeding: infant feeding risks in comparative perspective? Australas. Med. J. 5, 275283.

McCarter-Spaulding, D., 2008. Is breastfeeding fair? Tensions in feminist perspectives on breastfeeding and the family. J. Hum. Lact. 24, 206212.

Perrin, M.T., Goodell, L.S., Allen, J.C., Fogleman, A., 2014. A mixed-methods observational study of human milk sharing communities on Facebook. Breastfeed. Med. 9, 128134.

Palmquist, A.E.L., Doehler, K ., 2014. ontextualizing online human milk sharing: structural factors and lactation disparity among middle-income women in the U.S. Social Science & Medicine, 122, 140-147.

Thorley, V. 2009. Mother’s experiences of sharing breastfeeding or breastmilk cofeeding in Australia 1978-2008. Breastfeeding Review 2009 17, 1, 9-18.

Thorley, V., 2012. Mothers’ experiences of sharing breastfeeding or breastmilk, part 2: the early 21st century. Nurs. Rep. 2, 412.

Medical Anthropologist | Lactation & Infant Feeding Researcher | IBCLC | Podcaster | Blogger. Opinions are my own.

5 thoughts on “Who is milk sharing online?

  1. Very interesting article! I’d also be curious about looking into milk-sharing by another group that is often left out: active duty MILITARY mothers. They milk share due to the incredible challenges of military service (long hours, no time/place to pump, deployments, etc) but face a stigma for doing so. I wrote a blog piece about it and have linked to your post here. Fascinating stuff, thanks for posting!

    Liked by 1 person

    • HI! I love your blog!! We actually have many military mothers who have shared milk in our study!! Their stories have been some of the most compelling and interesting. The occupational barriers to breastfeed while active duty are really difficult to overcome. These moms are amazing! And thanks for linking back to here!


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