How do I know if my baby is gaining weight?
One of the most common questions new parents ask is:
“How often should I weigh my baby?’’
‘’How do I know if my baby is gaining weight?’’.
To answer that, we first need to understand what healthy weight gain actually looks like in those early days, weeks and months.
What’s Normal Weight Loss and Gain?
In the first three days of life, it’s expected for babies to lose some weight up to around 7% of their birth weight. If the loss is greater than this, it’s a signal to seek an assessment from someone skilled in infant feeding, such as an IBCLC (International Board Certified Lactation Consultant) or another suitably trained practitioner.
After day 3, we want to see steady weight gain around 30g per day, with a goal of getting back to birth weight by around two weeks old and continuing.
This can change again around 4 months when weight gain tends to slow to 15–20g per day.
Why Are Babies Weighed So Often in the Early Days?
There are a few key checkpoints where weighing your baby provides helpful insight:
- At birth – establishing the baseline
- At around 3/5days – checking percentage weight loss from birth
- Post day 3/5 days – looking for the shift to weight gain
- At 2 weeks – ensuring baby has returned to birth weight
These early weights help us track if feeding is effective and whether any additional support might be needed.
My baby is gaining weight but is receiving supplementation, and I want to exclusively breastfeed. What now?
It’s important to understand that supplementing your baby’s feeds can be a useful tool along your breastfeeding journey when suggested appropriately. However it’s not the final destination unless that’s your informed choice. If your baby is gaining weight appropriately with supplementation, that’s a positive sign that the current plan is working to support health growth of your infant, but what is being done to maintain milk supply and return to breastfeeding if this is your goal.
A skilled practitioner’s role goes beyond simply recommending or providing supplements. You deserve ongoing, compassionate support with a clear, personalised plan to help you return to exclusive breastfeeding if that’s your goal. This means:
- Working closely with you to understand why supplementation was needed and addressing those underlying challenges
- Helping you build confidence in breastfeeding techniques, such as latch, positioning, and recognising effective feeding cues
- Providing guidance on how and when to gradually reduce supplementation in a way that supports your milk supply and your baby’s growth
- Monitoring your baby’s progress regularly and adjusting the plan as needed
- Ensuring you have access to support whenever concerns or questions arise
If a practitioner discharges you while your baby is still receiving supplements without a clear, step-by-step exit plan toward exclusive breastfeeding, it’s okay to ask for more support or seek a second opinion.
Do I Need to Keep Weighing My Baby Every Few Days once they have regained their birth weight?
Probably not.
Once your baby is back to birth weight, weighing multiple times a week probably isn’t necessary, even if there are a few concerns. That might sound surprising, but here’s why:
There are other, often more meaningful ways to monitor how feeding is going, such as:
- Baby feeds at least 8–12 times in 24 hours
- You have you been shown what to look for in a good feed? Do you feel confident knowing what signs suggest baby is feeding well?
- You can hear or see regular swallows during feeds
- Your breasts feel softer after feeding (if breastfeeding)
- Baby is having plenty of wet and dirty nappies – 6 wet nappies (after 5 days old) and at least 2 poos per day (before 6 weeks)
- Baby is calm and settled between feeds
- Baby has periods of active feeding at the breast/bottle and does not fall asleep soon after latching
- Baby is able to get a deep latch onto the breast/bottle
- If you are a breastfeeding parent you are not experiencing any pain or discomfort
And here’s the most important bit:
- You don’t need a number on a scale to justify getting support.
- You are the parent. If something feels off, trust that instinct.
- You are allowed to ask questions, seek reassurance, and advocate for your baby.
You Deserve Support — Not Shame
Weight conversations can feel heavy, especially if they’re delivered without context or compassion. But here’s the truth:
- You haven’t failed.
- You’re not being judged.
- You can be supported to meet your feeding goals, whether that’s breastfeeding, bottle feeding, mixed feeding, or transitioning.
If you or your practitioner notice any signs that feeding might not be going as smoothly as hoped it should spark curiosity and careful support, not criticism. You deserve a care plan that meets you exactly where you are, helping you move forward with confidence, not leaving you feeling confused or blamed.
‘Faltering growth’ Is a Signal, Not a Sentence
When you hear that your baby has ‘slow weight gain’ or ‘faltering growth’ it can feel alarming. But it’s important to remember:
This isn’t a diagnosis. It’s a clue. A signal. A gentle nudge to take a closer look. What matters is the whole picture, not just a number on the scale.
Can You Weigh a Baby Too Much?
You might think: “More information is always better, right?” Well, not necessarily when it comes to weighing your baby and here’s why.
Frequent weighing can sometimes cause unnecessary anxiety, especially since baby growth isn’t a straight line. We like to see a prescribed average daily gain (depending on the age of the baby), but that doesn’t mean your baby gains exactly that amount every single day.
Confused? Don’t be! It’s actually normal to have a few days with little or no weight gain, followed by a big jump. For example, your baby might not gain anything for 4 days, then suddenly gain 120g on the 5th day. What really matters is the average over a longer time period.
If you weigh your baby every day and see the weight staying the same or fluctuating slightly, it can cause unnecessary worry, but this can be perfectly normal. I encourage you to pay close attention to the other ways mentioned within the blog to monitor how your feeding journey is going.
A baby weighed before and after a breastfeed, showing a 140g difference. This amount of milk transfer is equivalent to the average expected weight gain over approximately 4.5 days. This variation is normal and reflect fluid intake during a feed not true body weight gain or loss. When weighing is done too frequently, these natural fluctuations can appear alarming and lead to unnecessary concern.
What matters most is the pattern of weight gain over time, not individual measurements. That’s why consistent, well-timed weight checks and recognising signs of effective feeding are far more reliable than at-home daily weights.
Why the Timing of Weighing Matters
Another thing to keep in mind: weighing a baby before and after a feed will show a weight difference roughly equal to the amount of milk they just consumed.
For example:
- Baby weighs 4,220g before a feed
- Finishes a 90mL (3oz) bottle
- Baby weighs 4,310g after the feed
That 90g difference is like adding 3 days’ worth of typical weight gain all in one go!
Over longer periods, this isn’t a big deal, but if you weigh daily and sometimes weigh baby after feeding and other times before feeding, it can look like your baby hasn’t gained weight, when really it’s just the timing of the weigh-in.
Conclusion
The numbers on the scale are just one part of a much bigger picture. Remember, your attentive care, love, and responsiveness to your baby’s needs are what truly support their healthy growth and development.
If you ever feel uncertain or worried about your baby’s weight or feeding, don’t hesitate to reach out for support. Whether it’s from a lactation consultant, your healthcare provider, or a trusted support network.
