Avoid False Weight Alarms for Your Baby
By Rowena Bennett, RN, RM, CHN, MHN, IBCLC • Updated December 2025
Concerns about weight gain are common, especially when babies are weighed regularly. A single low or unexpected result can quickly raise alarm.
Having your baby weighed is one way to confirm that he’s growing well. When weight gain meets expectations, this can be reassuring. However, when it does not, it does not automatically mean there is a problem. In many cases, apparent changes in weight reflect normal variation or measurement factors rather than poor growth. This article explains common reasons for false weight alarms and how they can be misinterpreted.
- Weight does not increase in a steady line
- Day-to-day changes can reflect normal variation
- Measurement methods affect results
- Temporary plateaus are common in healthy babies
- Interpreting weight without context can cause unnecessary concern
What causes false alarms?
A false alarm means a parent or health professional becomes concerned about a baby’s growth when in reality his growth is fine. Concern stems from the method involved in weighing a baby or mistaken assumptions when interpreting the results. The following are examples of growth false alarms.
- Fluctuations in body fluids.
- Using different scales.
- Weighing baby in different clothing.
- Growth plateau.
- Variation in normal growth.
- Unrealistic expectations.
1. Fluctuations in body fluids
Scales measure total body weight. This includes body fluids, which constantly fluctuate. Included in the measurement of your baby's weight is ...
- How much milk is in his tummy.
- How much urine is in his bladder; and
- How full his intestinal tract is at the time.
If you were to weigh your baby multiple times on the same day you would see fluctuations in weight. In general, weight in the morning will be lower compared to weight in the afternoon and evening.
When weighing a baby from week to week, fluctuations in body fluids alone have the potential to cause a variance of up to 4 ounces (112 grams) for small babies, or up to 8 ounces (225 grams) for large babies. If for example one week you weighed your baby after a feed and at the time he had a full bladder and bowel, it might appear like he had a large weight gain. If the following week he was weighed before being fed and he had emptied his bladder and bowel it might appear like he gained very little, not gained at all, or lost a little weight during the week when this may not have been the case.
2. Different scales
What can appear to be a decline in a baby's weight gain could simply be due to using different scales. Scales require calibration and regular maintenance to ensure accuracy.
Using the same scales each time a baby is weighed will generally provide a consistent measurement, even if the scales are a little out of kilter. However, using different scales can provide very different results due to the possibility that one or both scales are in need of calibration.
3. Different clothing
If your baby is not weighed naked then variations in the weight of his clothing need to be considered. What might appear like a large or low weight gain would simply be that baby is wearing more or less clothing at the time.
4. Growth plateau
Babies’ pattern of growth is not consistent. While all babies grow over time, they don’t become a little longer and heavier each day. Growth occurs in a step-wise pattern. Just as babies go through growth spurts where they eat well, add extra weight and grow length-wise, there are periods where babies' growth plateaus. During this time baby's growth might remain stagnant and his appetite appear to be small.
5. Variation of normal growth
Babies are individuals. They don’t all grow at the same rate or follow the same pattern of growth. A baby’s weight gain or growth pattern could differ from what is generally considered as a typical growth pattern for babies without this being a problem. See Variations of normal growth for more.
6. Unrealistic expectations
It could be that you or baby’s healthcare professional are expecting him to gain average weight for age when this may be unrealistic for your baby. Another reason why a baby might not gain as expected could be due to one of a number of common mistakes made when assessing a baby's growth. See Top 10 baby growth assessment mistakes for examples.
What to do!
If you’re concerned about your baby’s growth, check if he shows signs of being a well-fed baby. If he displays signs that indicate he’s well fed, there’s probably nothing to worry about. It’s likely that the appearance of poor growth is a false alarm. In this case, have him weighed again in other another week.
Avoid jumping to conclusions. Making changes to your baby’s diet, or your feeding management in response to a false alarm has the potential to complicate the situation, and in some cases create infant feeding and growth problems that might not have previously existed. See Consequences of growth mistakes.
Written by Rowena Bennett.
About Rowena
Rowena Bennett (RN, RM, CHN, MHN, IBCLC) is a leading infant-feeding and sleep specialist and author of several books on infant feeding and behaviour, including the widely acclaimed “Your Baby’s Bottle-Feeding Aversion: Reasons & Solutions.” With over three decades of clinical experience across child health, midwifery, mental health, and lactation, she has helped thousands of families worldwide understand and resolve complex feeding challenges through her evidence-based, baby-led approaches.