What To Know About Weight Checks For Breastfed Babies

What To Know About Weight Checks For Breastfed Babies

Concerns about a baby's weight gain are one of the top stressors for breastfeeding parents. As a lactation consultant, "is my baby gaining enough?" is probably the question I get asked the most. It makes sense if you think about it. Unlike feeding your baby from a bottle, you can't see how much milk your baby is taking in at the breast. How are you supposed to know that your body and your baby are doing it right?

Enter baby weigh-ins…


The truth is that one of the best ways to tell if your baby is getting enough breast milk is by weighing them. While diaper output, time spent at the breast, and trying to gauge if your baby seems satisfied are all helpful ways to tell if your baby is getting enough, they are a bit subjective.

Some babies poop 5 times a day and aren't getting enough milk; some only poop twice a day and are growing well. Some babies finish the breast in 5 minutes and are totally full; others need 15 minutes on each side to get what they need! Finally, some babies seem totally content after feeding, but they have shut down and are conserving energy because they aren't getting enough calories. Other babies seem to want to feed "all the time," as though they are starving, but they are actually thriving.

Weight gain, though, is less subjective. If your baby is gaining weight at a steady rate, meeting milestones, and is generally healthy, we usually can surmise confidentially that your baby is getting enough breast milk.

The problem is that weighing a baby, especially if done frequently and under certain circumstances, can be extremely anxiety-producing for parents. Not only that, but certain ways of weighing a baby may give you incomplete information about your baby's status, your milk supply, or how much milk your baby is generally taking in while breastfeeding.


Sometimes a lactation consultant will do pre and post-feed weigh-ins during a consultation. The lactation consultant needs to use a very sensitive and accurate scale for this. The way it works is that your baby is weighed before feeding, and that weight is noted. Then your baby feeds, and is weighed again. The scale or your lactation consultant then calculates how much your baby's weight has increased, which can tell you how much your baby has taken in during that feed.

"During that feed" is the operative phrase here, though. While weighted feeds can be helpful in terms of giving your care team information about how much your baby took in during a particular feed, it is just that: a snapshot of one particular feed. Babies take in different amounts throughout the day, depending on the time of day, their behavior, their breastfeeding parents' behavior, how recently they've fed, etc.

Your lactation consultant uses this information as part of a larger picture to help understand what your baby is doing at the breast, along with other challenges they are dealing with. If your lactation consultant had weighed your baby at other feedings during the day, they might have gotten wildly different numbers. So it's really important not to take the weighted feed numbers as gospel. Try not to pay attention to them at all, if possible.


Periodic weigh-ins, usually at a pediatrician's office, are a better measure of how your baby is gaining weight. If you are worried about your baby's weight gain, it's best to wait at least a week before weighing your baby again because it can take that long to see results. Even then, you will understand the trajectory of your baby's weight gain even better if you weigh them monthly.

I don't recommend purchasing or renting a baby scale to weigh your baby at home. These are often unreliable, and the calibration can easily get thrown off. You are also just more likely to obsessively weigh your baby, which will not only stress you out but will not give you an accurate picture of their weight gain. Again, you need at least a week (or more) to assess whether a baby has put on weight.


As you think about your baby’s weight, there are a few facts about normal weight gain to keep in mind:

  • Babies are all different; some are meant to be small, some are meant to be larger
  • Babies gain weight in their own rhythm, and many tend to put on weight in spurts (those pesky growth spurts!)
  • All babies lose weight in their first few days of life; most babies will start to gain weight after your milk comes in (3-5 days after birth) and most will go back to their birth weight by a week or two
  • Breastfed babies usually gain about 4-7 oz per week during the first six months of life
  • It’s normal for weight gain to slow down by six months, to about 3-5 ounces per week
  • Breastfed babies don’t gain rate at the same rate as formula fed babies; they tend to bulk up in the first 6 months, and then gain slower (but steadily) in the second six months
  • Most babies need to eat very frequently, at least every 2-3 hours, and most need to nurse at night in order to gain weight
  • The majority of baby weight gain issues are because of infrequent feeding; spending a few days in bed with your baby, skin-to-skin, and letting them nurse as much as they want, often solves weight gain issues


Sometimes there really is an issue with your baby's weight, and this should not be minimized at all. If your baby isn't back to their birth weight by 1-2 weeks, or if they are slow to gain weight after that, you should take this seriously. Meeting with a lactation consultant who takes your concerns seriously, and comes up with a compassionate plan of care can be super helpful. Sometimes the answer will be as simple as a latch or positioning adjustment, but sometimes either you or your baby will have medical or anatomical differences that impact your baby's ability to gain weight.

Occasionally, breastfed parents will need to pump their milk, or consider short-term supplementation. Other times, different measures, such as surgery for a tongue-tie or trying herbs to support breast milk supply, will be advised. Some breastfeeding parents aren't able to bring in a full milk supply due to hormonal differences or breast anatomy differences; these parents may need to supplement on a long-term basis. Some will end up weaning, and that's okay too.


As a parent, you should always go with your instincts. If you think something is off with your baby’s weight gain, or your baby’s health in general, you shouldn’t hesitate to reach out to your pediatrician or lactation consultant for help.

At the same time, it’s important to keep weight checks in perspective. While they can offer some helpful information, they can often cause more stress and problems than they solve. It’s important to take information from a pre or post-weigh with a grain of salt, and you should shy away from weighing your baby on a daily basis.

When possible, try to look at the larger picture: Is your baby gaining weight at their own, steady pace? Are they feeding frequently, peeing and pooping often? Are they meeting milestones? Has your pediatrician said that they are healthy? If the answer to these questions is “yes!”, then you can breathe a deep sigh of relief because you are doing just fine!

Works Cited
Kellams A, Harrel C, Omage S, Gregory C, Rosen-Carole C. ABM Clinical Protocol #3: Supplementary Feedings in the Healthy Term Breastfed Neonate, Revised 2017. Breastfeed Med. 2017;12:188-198. doi:10.1089/bfm.2017.29038.ajk
Bright Futures – Academy of American Pediatrics. Nutrition Supervision. Accessed May 2022.
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Wendy (she/her) is a writer, editor, and IBCLC. She writes frequently about breastfeeding, parenting, and health. She believes in the power of providing families with smart, evidence-based information so they can make decisions that work best for their family. Find her

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