I'm Worried My Baby Isn't Growing (Failure to Thrive)
The short answer
Failure to thrive, now often called growth faltering, means a baby is not gaining weight or growing as expected. It is important to know that babies naturally shift percentiles in their first two years, and being on a lower percentile is not the same as failure to thrive. True growth faltering involves crossing two or more major percentile lines downward and usually requires medical evaluation to determine the cause.
By Age
What to expect by age
Weight gain in the first three months is typically rapid, averaging about 5 to 7 ounces per week. After an initial weight loss of up to 7 to 10 percent of birth weight in the first few days, babies should regain their birth weight by 10 to 14 days. If your baby has not regained birth weight by two weeks or is gaining less than 4 ounces per week, your pediatrician will want to evaluate feeding. Common causes at this age include difficulty latching, low milk supply, tongue tie, or formula preparation errors.
Growth velocity naturally slows slightly at this age but should remain steady. Babies typically gain about 3 to 5 ounces per week. If your baby's weight has crossed two or more major percentile lines on the growth chart, your pediatrician may want to investigate. It is worth noting that breastfed and formula-fed babies have different growth patterns, and the WHO growth charts, which are based primarily on breastfed babies, are recommended for all infants under 2 years.
As babies become more active with crawling and exploring, weight gain naturally slows to about 2 to 3 ounces per week. The introduction of solids sometimes leads to a temporary plateau as babies adjust. If your baby is losing weight or consistently dropping percentiles despite adequate feeding opportunities, your pediatrician may check for underlying causes such as food allergies, celiac disease, or metabolic conditions. Most cases of growth faltering at this age are related to caloric intake rather than a medical condition.
Toddlers grow more slowly than infants, and their weight gain may only be 3 to 5 pounds over the entire second year of life. Picky eating is very common at this age and can make parents anxious about growth, but most picky toddlers grow fine. If your toddler has dropped significantly on their growth curve, your pediatrician will likely evaluate their diet, look for underlying conditions, and may refer you to a pediatric nutritionist. The goal is to identify whether the issue is insufficient intake, increased caloric needs, or poor absorption.
What Should You Do?
When to take action
- Your baby is on a lower percentile but has been growing steadily along their own curve since birth
- Your baby dropped from a higher percentile to a lower one in the first 6 months and then stabilized, which often reflects finding their genetic growth pattern
- Your baby's weight dipped slightly during an illness but bounced back within a week or two
- Both parents are small in stature, and your baby is tracking along a lower percentile consistently
- Your baby has crossed two or more major percentile lines downward on the growth chart
- Your baby seems hungry all the time but is not gaining weight despite frequent feeds
- Your baby is significantly lighter or shorter than expected for their age and you are concerned
- Your baby is losing weight, appears listless or excessively sleepy, and is difficult to wake for feeds
- Your baby has signs of dehydration such as no tears when crying, sunken fontanelle, very few wet diapers, or dry cracked lips
Sources
Related Resources
Related Feeding Concerns
I'm Worried My Baby Is Aspirating During Feeds
Aspiration means liquid or food enters the airway instead of the stomach. Occasional coughing during feeds is common and does not usually indicate aspiration. True aspiration is less common and may present as recurrent respiratory infections, a wet or gurgly voice after feeds, or chronic cough. If you are concerned, a swallow study can provide a definitive answer.
Baby Biting Nipple While Nursing
Biting during breastfeeding is a common challenge, especially when babies start teething. It can be startling and painful, but it is almost always a phase that can be managed. Babies cannot actively nurse and bite at the same time because their tongue covers the lower teeth during proper sucking. Biting typically happens at the beginning or end of a feed when the latch is not active. With some gentle strategies, most babies learn quickly that biting ends the feeding session.
My Baby Keeps Choking on Food
First, it's important to distinguish between gagging and choking. Gagging is a normal protective reflex that helps babies learn to eat, while true choking is silent and requires immediate intervention. Most "choking" episodes parents describe are actually gagging, which is common and expected as babies explore new textures. However, if your baby frequently struggles with swallowing or shows signs of true choking, it's worth discussing with your pediatrician.
My Baby Coughs While Feeding
Occasional coughing during feeding is very common, especially in newborns who are still learning to coordinate sucking, swallowing, and breathing. It often happens with a fast milk flow or letdown. However, if your baby coughs with every feed or turns blue or has difficulty breathing, this needs medical evaluation to rule out swallowing difficulties.
Baby Falling Asleep While Nursing
It is very common for babies to fall asleep while nursing, especially in the newborn period. Breastfeeding releases hormones that make both you and your baby feel relaxed and sleepy. In most cases this is completely normal, but if your baby is not gaining weight well or consistently falls asleep within a minute or two of latching, it may be worth trying some gentle techniques to keep them feeding longer.
Baby Gagging on New Textures
Gagging on new textures is one of the most common parts of learning to eat and is a normal, protective reflex. It does not mean your baby is choking or that they cannot handle the texture. The gag reflex is positioned far forward on the tongue in young babies, which means they gag more easily. With consistent, gentle exposure, most babies gradually learn to manage new textures. Going at your baby's pace while continuing to offer varied textures is the best approach.