A Few Things to Know About Your Baby’s Weight

What’s normal and what’s worth checking into, in the first year!

There are so many things that parents worry about during their baby’s first year, but one of the most important is weight gain. Particularly for breastfeeding moms, it’s hard to tell if your little one is getting enough milk. With formula, it’s measurable; with breastmilk, not so much! So measuring their growth through weight is a valuable way to make sure baby is thriving.

Growth charts to follow for your baby

The most highly recommended method for checking your baby’s weight is to use the WHO (World Health Organization) Growth Charts. These were developed using data from six countries, including the US, based on breastfed babies. This is important since earlier charts were often based on formula fed babies and the weight gain patterns can be quite different.

In general, breastfed babies grow more quickly for the first four to six months than formula fed, but then the plateau. The opposite is true for formula fed, who grow more slowly at first and then start picking up weight. The result was that many breastfed babies were being categorized as ‘underfed’ or not thriving, when in fact, they were perfectly hydrated and fed.

What’s normal weight gain, for breastfed babies?

First off, it’s completely normal for newborns to drop a couple of ounces after they’re born. Call it water weight, but basically, it is related to their skin losing some of the moisture that it had retained in the womb.

Most babies will return to their birth weight by day 10. If your baby isn’t coming back up close to birth weight by 10 days old, it’s worth checking in with the doctor.

Up to the age of 3 months, most babies will gain an average of 6 oz per week. Again, this is an average. Some will be a bit more and some a little less, which is why the curves as used in the growth charts (above) are more accurate than a standalone figure.

Weight gain will slow down around months 4 to 6, to an average of 4 – 4.5 oz per week. Over six months, the average drops to 3 oz per week.

In total? The average is doubling of birth weight by 4.5 to 5 months of age and tripling by their first birthday.

When should weight be a concern?

The WHO charts show that the best balance is to look at height AND weight. A child who is in the 95th percentile for weight AND height is likely doing just fine. If they’re in the 60th percentile for weight but only the 5th percentile for height, there might be a concern of baby being overweight.

Babies gain weight more easily if they are formula fed, in part because they learn to continue drinking until the bottle is empty. As a result, they might be getting more in their daily intake than they actually require. Breastfed babies will stop feeding when they are full, as there is no notion of the ‘empty bottle’.

If baby is breastfeeding but not gaining much weight, it could be an issue with latching, where baby doesn’t actually have a tight latch on the nipple and isn’t getting enough milk as a result. Mom can actually compress her breast during feeding, effectively expressing milk into baby’s mouth, to try and improve the flow. The important thing is to look at baby overall. While he or she might be lower on the growth charts, if they are otherwise happy and healthy, they just might not be a big eater. Be careful not to panic!

However, if baby isn’t gaining, or worse, is losing weight, it’s best to consult with a doctor and / or lactation consultant through the doctor’s office. It’s also possible that mom’s milk supply has decreased and baby is simply not getting enough.

As to how much a baby should be eating as time goes on? We’ll cover that in a future post! In the meantime, if you have concerns about your baby’s weight, check in with your postpartum doula. She can help you to decide if baby’s weight gain is normal or if it’s time to check in with the doctor.