The problem with pumping

Why the new science of breast milk suggests that the (actual) breast is best

Awkward breast pumping experiences are a rite of passage for most mothers I know. First, the quest to find a private space, and winding up in a grungy storage closet or basement bathroom (I’ve pumped in both; friends have pumped in a parked car, behind the altar in an empty church, and between makeshift cardboard dividers at a crowded conference session). Next, there’s the unwieldiness of hooking up one’s breasts to a contraption that resembles the flower-faced monster in Stranger Things, and needs to be disassembled and disinfected every time it’s used. Everyone has an awful pumping story: the window washer who descends into view just as your milk lets down; the boss who leads a tour group of visiting colleagues into your pumping room; the nipple that goes rogue and sprays milk all over your laptop.

Given this solidarity of the pump, Sarah Bowen, a sociologist who studies food and families, was surprised on a trip to Sweden to discover that most of the mothers she met there (including a doctor!) had never interacted with a breast pump. “Many of the Swedish moms I talked to didn't pump,” she says. “They breastfed while they were home with their babies.” Of course, Swedish families receive 480 days of paid parental leave from work, so they don’t run into the “Human Milk Gap” that historian Jill Lepore has written about; the nine months or so that stretch between the physician-recommended year of breastfeeding and the 12 weeks of leave that many U.S. mothers get (if they’re lucky enough to get leave at all). As Bowen posted on Twitter, “I think we underestimate in the US how much our unsupportive system shapes thinking about mothering. Talk about breastfeeding is really about pumping (having access to pumps, places to pump), instead of whether moms have time [and] space to breastfeed (and generally care for kids).”

This is ironic, because the more we learn about the science of breastfeeding, the more we discover that its magic isn’t just in the milk itself, but in the interchange that takes plan between mother and infant during the act of feeding. This doesn’t just mean the physical closeness and touch that take place during nursing, although those are clearly both psychologically and physiologically beneficial to mother and baby. But also, new research suggests that the very elements that comprise breast milk are delicately calibrated to context, like the time of day that feeding occurs and the bacteria that mother and infant exchange.

Milk as chrononutrition. Any parent who’s endured the haze of newborn sleep-deprivation knows that most infants scramble their days and nights. Their circadian biology – the daily rhythms that characterize sleep, feeding, and energy levels – develops over the first months of life, shaped by recurrent environmental cues like light, sound, and activity. Breast milk may represent another one of those cues, and is rich in hormones and other compounds that vary predictably across the day. Morning milk abounds with mobilizing cortisol, whereas night milk is rich in calming melatonin. When infants are routinely fed pumped milk that isn’t time-matched, their circadian signals can get crossed; a bottle of morning milk consumed at night may be the neonatal equivalent of a shot of espresso right before bedtime.

The fact that so many infants consume “mistimed” milk is a particularly modern problem. Before refrigeration and breast pump technologies, milk could only ever be fed directly from the breast, served right at the point of sale. But now, mothers can pump around the clock, and their infants can consume that milk on a completely different clock. This affects infants in medical or foster care settings as well as individual homes. For example, infants in Neonatal Intensive Care Units (NICUs) are often too fragile to feed at the breast, so they get exclusively pumped milk. Many other infants access donor milk from milk banks. But NICUs and milk banks rarely log the collection time of the milk they use.

We don’t know if there are long-term effects to routinely feeding infants off-time milk, because research on breast milk as “chrononutrition” is still in its infancy. (Jennifer Hahn Holbrook at UC Merced is one of the leaders of this new field). But increasingly, research has pointed to circadian biology as an important component of health, one that’s closely tied to mood, stress, appetite regulation, and sleep. Infants develop their circadian rhythms on different timetables, which explains why some parents enjoy long stretches of nighttime sleep in the first months after birth, whereas others struggle to get on schedule. The role of milk timing might explain some of this variability and encourage pumping mothers to, at the very least, label the milk they pump by the time of day they pump it.

Milk as conversation. The composition of breast milk reflects mothers’ hormonal milieu, which means that the hormones in milk can change based on more than just time of day. At the very least, it means that we can think about breast milk as a conversation, one that fluctuates as mothers encounter both challenging and calming experiences and that delivers cues to infants about the kind of world they can expect to enter. That conversation is a two-way street, too; there’s increasing evidence that infant saliva feeds back to mothers and helps to galvanize the production of immune-boosting compounds. The conversation doesn’t just include the biology of the breast milk itself, but also the coregulation of heart rate, temperature, and breathing that occurs when mother and infant are physically close. This coregulation scaffolds the development of the infant’s own self-regulation capacities, and helps build the bond between mother and child. When milk is pumped and then served to infants hours later, some of the immediacy of that conversation is lost, as is its pleasure. In short: Milk is more than the sum of its parts, so let’s not mix up the nutrients in milk with the magic of nursing an infant.

Let me be clear: I’m not knocking the breast pump. In fact, it’s a marvelous invention, one that allows new moms to travel and work and come untethered from their baby for more than a few hours at a time, enabling work and travel and all the delights of being a free agent, out in the world. Without the pump, I would have missed a friend’s wedding, an important research conference, and innumerable meetings that really mattered. But because the pump is so convenient, it fits all-too-neatly into a workaholic culture that values the office above all. It makes it all too easy for a workplace to claim it is “baby-friendly” without needing to truly restructure to tolerate the fuss of an actual baby. The pump is a useful tool, but a technology that sentences women to the tedium of thrice-daily pumping session is not such much a liberation as another form of tether. And if our collective definition of a “family-friendly workplace” just means a pumping room with a refrigerator, mothers need to demand more from their employers and from our culture. Real maternity leaves, like the six months or more that we see in most developed countries, would do more to foster infant health than the most tricked-out pumping room on the planet.

I’m also not knocking mothers who can’t or don’t breastfeed for a variety of reasons, or who need to pump instead of nursing at the breast. It’s easy for “breast is best” discourse to get toxic, judge-y, and shame-y. Rather, as with so many topics that fall under the childrearing umbrella, we must turn our focus from individual choices to collective actions. As a society, we all benefit from the future potential that is maximized when a baby is cared-for and thriving. That means we need to publicly, not just privately, invest in policies that maximize infant health. For many families, that means making breastfeeding easier and making sure moms have more time off to rest and bond after birth. It means creating public spaces that are welcoming to nursing mothers and babies. Handing a busy, stressed working mom a pump and telling her that she’s a bad mom if her baby doesn’t get a full 12 months of milk is not the same as creating an ecosystem that supports nursing.