Why Isn’t Your Baby Gaining Weight? And When Should You Worry?

All babies grow at different paces. For most, growth after birth is fast and easy. But some babies do not gain weight as quickly as expected, even though they may have a healthy appetite. We get concerned about lack of weight gain because it can lead to problems like developmental delays, behavioral concerns and difficulty fighting infections. As a parent, when should you start worrying about your baby’s weight?

If growth problems continue over time, it is called “failure to thrive.”  Your pediatrician monitors weight at all well child visits and will let you know if this is a concern for your child. There are three reasons why babies do not gain weight: not taking in enough calories, not absorbing calories or burning too many calories.

Understanding the Causes of Failure to Thrive

Full-term newborn infants should take in about 1.5 to 2 ounces of breast milk or formula about every 3 hours. Premature infants need more calories than term babies. Some babies are difficult to feed, have reflux or vomiting with feeds, have trouble staying awake for feeds or have trouble swallowing.

Other children consume enough calories but still have difficulty gaining weight as expected.  These children may have trouble absorbing food and using the calories given to them. Certain intestinal issues, such as Celiac disease, food allergies and diarrhea, can keep babies from being able to utilize the food given to them to grow.

Lastly, some children with failure to thrive use calories very quickly because they have an increased need for calories. This would include children who have to work harder to breathe, were born early or have certain heart abnormalities. These children require extra calories for adequate weight gain.

Helping Your Baby Gain Weight

When your child is first struggling to gain weight, your pediatrician will give you several things to try at home to increase your baby’s weight. If those strategies don’t work, you might be asked to come to the hospital for closer monitoring.

If your child needs to come into the hospital for failure to thrive, please know that we will work together as a team to understand why your child is not gaining weight. If babies are unable to take in enough breast milk or formula, we can increase the amount of calories in their food. If there are other health problems causing the poor growth, we will work to quickly find a diagnosis and get your child the right treatment.

We will monitor your child very carefully, keep track of all calorie intake and output and watch feeding times. We will collect health information on your baby and perform a physical exam. We also may run blood, urine and stool tests to look at electrolyte levels, kidney function, thyroid function, iron levels and signs of allergies.

Our nutrition team, skilled nurses and psychological team are very good at finding ways for babies to eat enough calories for adequate weight gain. No matter the cause of your child’s problem, we all work on the same team to help your baby gain the weight he or she needs to thrive!