The rise of milk volume measurement products and the implied lack of confidence in maternal bodies

Today, I was stunned to see a press release for a new breastfeeding measurement tool, the MilkSense. From a research standpoint, I will admit that any handheld device that allows me to accurately measure milk transfer and is small enough to fit in my backpack makes me excited. Those highly accurate baby scales are heavy when they have to be moved by hand at altitudes greater than >10,000 feet. But, when I see devices like this, I, the researcher, want to be the product’s intended audience. Sadly, I, and other researchers, am never the target audience.

It is always mothers.

And that is a huge problem. 

Why? Because what devices like the MilkSense and the recently discontinued Milk Screen test strips actually serve to do is not to increase maternal confidence in the capacity to produce milk, but to call into question the ability of breastfeeding to meet an infant’s needs. 

Figure 1: MilkScreen. These were test strips used to calculate milk volume. Now discontinued.

Figure 2: MilkSense. This device measures electrical changes in the breast and calculates volume based on the changes. It is now packaged with a scale for weighing the baby.

Human milk and human babies evolved together, and hands down, human milk is the best option for human babies. Certainly, there may be individual instances that differ, but for the global whole, human milk is the best.  Commercial infant formula is a fairly recent development, and before that, while the use of milk substitutes and supplements was common, breastfeeding was the de facto method of feeding infants.  It is incredibly unlikely we as a species would have survived and produced some 7 billion humans if human milk wasn’t so good at meeting infant needs. So why then, are we so convinced that women can’t breastfeed?

Well, as discussed in the multi-part series “who manages themammaries”, “I didn’t make enough milk” is the single most common reason women in the United States give for cessation of breastfeeding.  However, making enough milk is, in itself, a problematic concept. How do you define not making enough milk? Too often, common behaviors such as closely spaced feedings, are used as a yardstick for “not enough milk”.  

 

Baby wants to nurse every two hours. Mother uses MilkSense. Sees she is only transferring 60cc of milk to the infant (2.02 ounces) per feeding.  Googles this, and sees that formula fed and babies receiving expressed human milk usually take 3-4 ounces per feeding. Decides she does not have enough milk, and starts supplementing the infant with formula. 

Except, if we do the math, she had plenty of milk! Two ounces every two hours is 24 ounces a day -  and this is within the range of normal milk intake for a breastfed baby (19-30 oz).  Why then, is she only making 2 ounces per feeding?

Because that day, or that feeding, that was likely all the infant wanted. Figure 3 shows the average stomach size of an infant at three different ages. Two ounces may perfectly fit that tiny stomach. For another baby, four ounces may be the perfect amount, and chances are, this baby may be taking 120 ccs (4 ounces) at each feeding.  Breastfeeding is the ultimate supply and demand system: the infant demand typically sets the supply. 

There are of course, some exceptions. Mothers with biological insufficient milk syndrome, often the result of insufficient glandular tissue or similar, may never meet the infant’s demand. This is, as I have said elsewhere, part of normal human biological variation. 2-5% of people’s pancreases fail to make insulin. Two to five percent of people cannot make milk. But when the population levels are at >50%, then we have a problem. If 50% of people suddenly developed Type 1 diabetes over the next decade, we’d assume that something was terribly, terribly wrong in the environment and not that it was a biological reality that 50% of people cannot make insulin. Why then, do we buy this argument for milk synthesis?

If you answered “it’s the economy, stupid,” you’d be about half right. Breastfeeding has become a major business. A market that used to start and end with breast pumps and boppies now has a tremendous number of additional products and “tools” available to mothers. And while numerous options of pumps have allowed many women to meet their breastfeeding goals while engaging in other activities, much of the industry thrives on the construction of maternal anxieties about making enough milk to feed a baby. MilkSense, MilkScreen, and other products like this attempt to quantify milk transfer without a complete picture of the breastfeeding relationship between the mother and baby.  Feeding frequency is as important as volume transferred per feeding – and volume transferred may have more to do with stomach capacity and hunger than production capacity of the breast. Maybe yesterday was 90F, and in attempt to stay hydrated, the infant that usually nurses every 3-4 hours wanted to nurse every hour to eliminate thirst. Today, the infant is less interested in nursing, because it is cooler, a tooth aches, older sibling is distracting. But the volume tests don’t take into account normal infant behavior. Instead, breastfeeding is re-framed as milk production. The objective is uniform production across multiple days, similar to factory production of goods. But breastfeeding is not factory production, rather it is a biological practice, informed by maternal behavior, infant demand, and social factors. 

Figure 3: Normal variation in milk production across a single day. Photo by Megan Hart.

While the use of these products may serve to increase maternal anxieties – another legitimate concern may be that they may become substitutes for far more successful breastfeeding interventions - namely social support. Peer-based breastfeeding support, WIC breastfeeding support, professional breastfeeding support, and even web-based breastfeeding support groups focus on the mother and the baby, not quantifying production. The motto “watch the baby, not the clock” may be “watch the baby, not the device, the scale, the pump, the app.” Further, the substitution of such devices for expert care may identify low milk supply in some instances, but cannot offer solutions. Instead, you have a mother in isolation with a device or test telling her she does not make enough milk. Breastfeeding support however, would be able to investigate why – and refocus the “problem” as not one of production. 

MilkScreen has been pulled from the US market, and it is unclear what the fate of MilkSense will be.  MilkSense is not currently available in the United States and only recently became available in Israel.  It will be interesting to see the public response to MilkSense.