It’s normal for babies to lose weight after birth. We weigh baby a few times during the first week to make sure baby hasn’t lost too much.
The nadir of loss hits around 48-72 hours. Loss up to 10% is ok. Losing more doesn’t mean you are failing or baby is starving, just that you need more support.
It can take baby two weeks to get back to birth weight!
Babies lose weight because:
- You produce only 1-4 teaspoons of colostrum per day, until your milk comes in
- Baby’s tummy is the size of a marble
- Nursing is exercise! At first, baby is burning more energy than they are taking in
- Some babies take longer to learn to transfer milk, even when milk is abundant
- Much of the weight loss is brown fat being burned. Some of the loss is mild dehydration
- If you get IV fluids during birth, it may cause overhydration which will add to baby’s birth weight. Baby will pee the excess fluid during the first 24 hours, which may make baby appear to have “lost too much weight” at the next check
If you are nervous about your baby losing weight between checks, look at:
- Output. Baby needs 1 wet for every day it is old, up to 6 days, when we expect 6 or more wets a day. 1 poo daily is preferred. If output is down, call your provider
- Behavior. Is baby cycling through different behaviors every few hours? Constant lethargy or inconsolable crying mean baby is struggling
If a baby loses more than 10%, WE DON’T PANIC. Instead, we call a great lactation expert! Until the lactation appointment we:
- Review nursing basics
- Hand express or pump after feeds and supplement whatever we get by dropper or cup
- If pumping/expression isn’t producing much, continue hand expression as it can, over time, increase milk supply. At this point you can supplement donor milk or formula
- Keep an output and behavior log and call the provider with concerns