Weighing in on weigh-ins

Baby being weighed on scale (image via Flickr Creative Commons)
Baby being weighed on scale (image via Flickr Creative Commons)

The idea that milk supply isn’t what it should be is the top reason for moms to cease breastfeeding. This concern runs deep; what is more primal than a mother’s need to feed her child?

In the few minutes or hours a lactation professional spends with a mom, we have to counteract years of immersion in a culture that doesn’t support breastfeeding. Nearly every woman issurrounded by other women who say they could not breastfeed because they didn’t make enough milk or their babies weren’t satisfied with what they could get from the breast. Well-meaning friends, family members, and medical care providers can say or do things that chip away at confidence, such as with seemingly innocent comments like, “How can she be hungry again?  Maybe you should give her a bottle and fill up her belly.”

Our culture likes numbers, too. How much did that little guy weigh when he was born? What percentage of that weight did he lose within the first few days? How many ounces is he gaining a day? What percentile is he in? How much is he taking in per feed? How often does he feed and for how long?

Numbers aren’t all bad. A lactation counselor or consultant will probably ask for a rough estimate of how many times per day you feed your baby and for roughly how long. (“Too many to count” and “I have no idea; until he’s done?” are acceptable answers.) While we “watch the baby, not the clock,” sometimes the numbers can give us a clue; for example, if a mom says she’s breastfeeding her newborn every three hours, 10 minutes on each side, that might be a big clue into a baby’s low weight gain.

There’s a trend these days of hosting breastfeeding support groups run by some sort of lactation professional (though often not an IBCLC) where a scale is present for weekly weigh-ins. The idea, of course, is to reassure moms that their babies are gaining on a steady curve or taking enough milk in at each feeding. For many reasons, I’m not fond of this practice.

“So,” you might be asking. “What’s your problem with baby weigh-ins? Why do you gotta go and complain about everything? Doesn’t this help moms and encourage them, when they have hard numbers to go on?” I’m glad you asked! I’ll point out a few of the issues I can see.

Scales are not always accurate, and how we use scales makes their numbers even less accurate. Dr. Jack Newman (if the science of lactation had holy men, he would be one of them) writes a lot about the accuracy—or lack of accuracy—of scales. In a Facebook post about percentage of weight loss, he writes:

Different scales weigh differently. I have seen two scales weigh 400 grams (14 ounces) different for the same baby weighed minutes apart… I have seen two scales of the exact same make by the same manufacturer weigh the same baby 85 grams (3 ounces) and this is probably not unusual…
Even if the scales weigh exactly the same, error in reading the scale or marking down the weight are made frequently. We have documented one baby who was weighed at birth at 2.58 kg (5lb 11oz) and 5 hours later weighed 3.1 kg (6lb 13oz)…what if the weigh [sic] were taken the other way around? Going from 3.1 kg at birth to 2.58 kg the next day is a loss of 17% of the baby’s weight. Can you imagine the panic?
A scale that is properly calibrated (many are not), is true only to itself, not to other scales.
 Consider also that babies need to be in exactly the same state of undress at each weigh-in, preferably naked. And are we making sure to weigh wet/dirty diapers along with the naked baby after he’s had a feed and a giant poop, then adding the weight of a clean diaper to the inital weight to ensure that we’re considering more of the variables? The time of day we’re weighing a baby might make a difference, too; our weights fluctuate throughout the course of the day.

So, while weighing a baby to track a growth curve, in order to be as close to accurate as possible, we should always use the same, properly calibrated scale, with all variables remaining constant from weigh-in to weigh-in. It’s not difficult to imagine a scenario where a baby is weighed at a doctor’s office and, later, at a baby weigh-in, and there being a difference significant enough to elicit concern.

Sometimes, when there is a concern about how much milk is transferring to a baby while he is sucking at the breast, a pre- and post-feed test weight might be done. This is when a baby is weighed, fed (sometimes for a certain amount of time, sometimes until satisfied; the latter would be more accurate but isn’t always what is requested), and weighed again on the same scale. (There is actually a little more to it than that; there is lots of room for error.) Test weights can be a useful tool, but they must be done with an eye toward the big picture and keeping many factors in mind. Again, from Dr. Newman:

How much is a baby supposed to get from the breast even if the weights are accurate? We don’t know. Breastmilk is magic and defies the logic of the “bean counters”.

…Most mothers will agree that they have more milk in the morning than in the evening. So if the milk intake is measured in the morning, the result may be falsely reassuring. If measured in the late afternoon or evening, the result may be falsely concerning.

It is well known that the amount of fat in breastmilk is variable so that 30 ml (one ounce) of high fat milk may be a lot more satisfying than 30 ml lower fat milk and just as adequate for the baby’s growth as considerably more formula. And I don’t me(an) “hind milk”. Studies also show that breastmilk fat content varies throughout the day.

It is also well known that anxiety can decrease the milk ejection reflex and thus, how much milk the baby will get. Being “put to the test” of test weighings can be very anxiety producing and affect the intake of milk by the baby.

So, scales may not be accurate and it’s tricky to do weighted feeds. But what about mothers? Aren’t they reassured by numbers? Some might be. But consider this: If a mom needs more reassurance than we can give through counseling, without help from scales, about how a baby is getting enough milk, how would giving her information from an inaccurate source help? It might take just one weight that is lower than expected to undermine whatever confidence she had been building. Some moms may not trust themselves or their own perceptions and may wish to rely upon outside perspectives; is it a good idea to give them tools that may be lying to them? I’ve been there; it isn’t easy, even for seasoned parents, to keep their fears and anxiety in check. There may be moms who are 100% reassured by the numbers on a scale, but there may be others who cannot quite trust it. Wouldn’t it be most fair, to both parties, to give them other tools that give them a greater perspective and teach them to trust their bodies and their babies?

And, finally, when weigh-ins happen in a group setting, you may not get enough one-on-one time with a lactation support person to receive enough information to keep these weights in context. Furthermore, since there less privacy than you would have during an individual appointment, other moms may be listening to what is going on with you and your baby, and some of them might try to apply that information to their own situation, without having help looking at the big picture and their selves and their babies. You never know who is listening, and how they will internalize what they hear.

To summarize:

  • The accuracy of scales is questionable, even if you’re using the same scale from time to time.
  • There is much room for user error.
  • Even when trying your best to ensure accuracy, there are other, less easy-to-quantify factors to keep in mind, such as how much milk a mom may make at different points of the day; fat content being variable and volume not necessarily being the only consideration in regard to if a baby is getting “enough”; and simply not knowing what amount is “enough” for a baby.
  • There is still the overarching consideration of whether or not we should be treating normal breastfeeding as something that requires lots of gadgets and quantification. It can be hard to trust the process, but does this mean we should stop trying?
  • In group settings, what is reassuring to one mom may not be to another.

To be clear, I think that in certain settings—such as group care situations where several moms bring their babies for regular well checks—the benefits may easily outweigh the potential pitfalls. I also think it is possible to do support groups with weigh-ins well, if they are staffed by an IBCLC who will take the time to assess any concerns, have one scale that is regularly recalibrated, and keep in mind the big picture. But considering how difficult it is to hit all of the finer points, I don’t think it is likely that it is happening, and I think we would be serving mothers better if we relied on good old-fashioned counseling skills, rather than newfangled baby-weighing devices.


  1. Agree! Agree! Agree!

  2. I wish this could be handed out as required reading to every new mama.

  3. I happened upon this article and an going through this very thing with my three month old son. He has been gaining on average around 3 to 4oz a week. From what I’ve read that is definitely on the low side and his dr flipped out and told me I had to start supplementing with formula. Never once did he mention hey maybe you should visit lactation to troubleshoot with you. Just immediately said you need to give him a bottle asap with formula and give him add much as he will take. I of course second gUess myself and like a dummy followed what he said to do. My son freaked out (of course he did because he hasn’t had to eat something foreign before) and for a solid day refused the breast and the bottle. It was torture! I will be heading to lactation Monday for an appt to troubleshoot. Any ideas for me. He weighed 11 pounds 11 ounces two weeks ago and now is 11 Pounds 14 ounces. He is only satisfied nursing on one side and flips out when I try to switch breasts on him. I do not want to supplement:( but he needs to gain weight I know I have plenty of milk for him too.

    1. Hi, Whitney! I’m glad you’re making the move to see a lactation professional. IBCLCs have the knowledge and tools to be able to do a full evaluation of how breastfeeding is going and help you to figure out the best way to take care of any problems—if there are any. Whoever you visit should look at the whole picture and come up with strategies that work for you. A test weight feeding (where your little one is weighed before and after a feeding) may be useful in this case, and in the context of the big picture.

  4. I probably had a stupidly easy time of it – but I really did enjoy weigh ins. My little one was born about exactly average sized and then has wiggled around the bit bigger than average line ever since (sort of doing a little dance around the 75th centile) so I’ve never had anything to worry about.

    Where I live you go to a weigh in clinic with the health visitors (nurses with additional baby training). You sign in and get a letter and then you sit around thinking that this room is insanely hot and look at the other babies. Your baby wants some milk, beacuse babies always fancy a bit of milk. After a while they call out your letter and you go and take all your babies clothes off and they don’t get very cross because the room is insanely hot.

    The health visitor says inane things about your baby being pretty (to everyone – I heard) and you preen a bit. They ask how you feed and you say you breast feed and they tell you that you are very good for a few minutes (you preen some more). You put all the clothes back on your baby and escape the insanely hot room feeling like you’ve just been in an episode of Call the Midwife. Plus there are nice ladies from the breastfeeding network there to be helpful as well.

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