Most kids steadily gain weight and grow quickly within the first few years of life. But in some cases, kids don't meet these expected standards of growth. When this happens, it's called "failure to thrive."
Doctors say children "fail to thrive" when they don't gain weight as expected. Often, these kids also have poor linear (height) growth.
Many things can cause failure to thrive, including illnesses and eating problems. Once doctors find the cause of the problem, they can work with families to help get a child back into a healthy growth pattern.
About Failure to Thrive
Although it's been recognized for more than a century, failure to thrive lacks a clear definition, in part because it's not a disease or disorder itself. Rather, it's a sign that a child is undernourished. In general, kids who fail to thrive don't receive or cannot take in, keep, or use the calories that would help them grow and gain enough weight.
Doctors usually diagnose the condition in infants and toddlers — an important time of physical and mental development. After birth, a child's brain grows as much in the first year as it will grow for the rest of a child's life. Poor nutrition during this period may have lasting harmful effects on brain development.
Most babies double their birth weight by 4 months and triple it by age 1, but kids who fail to thrive usually don't meet those milestones. Sometimes, a child who starts out "plump" and seems to be growing well may gain less weight later. After a while, height growth may slow as well.
If the condition continues, undernourished kids might:
lose interest in their surroundings
avoid eye contact
not reach developmental milestones like sitting up, walking, and talking at the usual age
A number of things can cause failure to thrive, including:
Not enough food offered. In some cases, parents mistakenly cause the problem. Sometimes a parent measures formula incorrectly, causing an infant to get too few calories. Problems with breastfeeding or transitioning to solids also can cause failure to thrive. Parents who worry their child will get fat may restrict the amount of calories they give their infants. And sometimes parents don't pay enough attention to their children's hunger cues or can't afford enough food for their children.
The child eats too little. Some children have trouble eating enough food because of prematurity, developmental delays, or conditions like autism in which they do not like eating foods of certain textures or tastes.
With reflux, the esophagus may become so irritated that a child refuses to eat because it hurts. Persistent diarrhea can make it hard for the body to hold on to the nutrients and calories from food. Cystic fibrosis, chronic liver disease, and celiac disease all cause problems with the body's ability to absorb nutrients. The child may eat a lot, but the body doesn't absorb and retain enough of that food. Kids with celiac disease are allergic to gluten, a protein found in wheat and other grains. The immune system's abnormal response to this protein damages the lining of the intestine so it can't absorb nutrients properly.
Food intolerance. A food intolerance, which is different from a food allergy, means the body is sensitive to certain foods. For example, milk protein intolerance means the body can't absorb foods that have milk proteins, such as yogurt and cheese, which could lead to failure to thrive.
An ongoing illness or disorder. A child who has trouble eating — because of prematurity or a cleft lip or palate, for example — may not take in enough calories to support normal growth. Other conditions involving the heart, lungs, or endocrine system can increase the amount of calories a child needs and make it hard for the child to eat enough to keep up.
Metabolic disorders. Metabolic disorders are health conditions that make it hard for the body to break down, process, or take energy from food. They also can cause a child to eat poorly or vomit.
Sometimes a mix of medical problems and environmental factors leads to failure to thrive. For instance, if a baby has severe GER and is reluctant to eat, feeding times can be stressful. The baby may become upset and frustrated, and the caregiver might be unable to feed the child enough food.
Other times, doctors aren't sure exactly what causes the problem.
Many babies go through brief periods when their weight gain levels out, or they even lose a little weight. This is not unusual. However, if a baby doesn't gain weight for 3 months in a row during the first year of life, doctors usually become concerned.
Doctors use standard growth charts to plot weight, length, and head circumference, which are measured at each well-child exam. Children may have failure to thrive if they fall below a certain weight range for their age or fail to gain weight at the expected rate.
To see if there's a problem, doctors will ask for a child's detailed health history, including a feeding history. This helps doctors see whether underfeeding, household stresses, or feeding problems might be to blame. A nutritionist or other health care professional also may track the calories in a child's diet to make sure the child is getting enough.
Doctors might order tests (such as a complete blood count or urine test) to check for underlying medical problems. If a particular disease or disorder is suspected, the doctor might order other tests to check for that condition.
Treatment for kids who fail to thrive involves making sure that the child gets the calories needed to grow and addressing any underlying feeding issues. This often requires the help of a care team that may include:
the primary care doctor or pediatrician
a registered dietitian to evaluate the child's dietary needs
a social worker if a family has trouble getting enough food for the child
psychologists and other mental health professionals if there are any behavioral issues
specialists (such as a cardiologist, neurologist, or gastroenterologist) to treat underlying health conditions
Usually, kids who have failure to thrive can be treated at home along with regular doctor visits. The doctor will recommend high-calorie foods and may place an infant on a high-calorie formula. Depending on the child's feeding habits, doctors may recommend offering foods of certain textures, spacing out meals to make sure children are hungry, avoiding "empty" calories like juices and candies, and other strategies depending on the child's condition and family situation.
In cases of severe failure to thrive, a child who is not growing with initial treatment may need tube feedings. In tube feedings, a tube is put in that runs from the nose into the stomach. Liquid nutrition is provided at a steady rate through the tube and is usually given at nighttime only. The child can continue with daily activities and eat freely during the day. Once he or she starts getting more calories, the child will feel better and will probably start to eat more on his or her own. At that point, the tube can be removed.
Children with extreme failure to thrive might need to be treated in a hospital. There, they will be fed and monitored around the clock for 10 to 14 days (or longer), until they gain some weight. After that, it still can take months until the symptoms of severe malnutrition are gone.
How long treatment lasts can vary. Weight gain takes time, so it might be several months before a child is back in the normal range. When the condition is due to a chronic illness or disorder, kids may have to be monitored regularly at their doctor's office. In those cases, treatment may take even longer, perhaps for a lifetime.
If you're worried that your child is failing to thrive, remember that many things can cause slower weight gain. For instance, breastfed babies and bottle-fed babies often gain weight at different rates in the early newborn period.
Genetics also play a big role in weight gain. So if a baby's parents are slim, the baby may not put on pounds quickly. However, infants should still gain weight steadily. As a general guideline, babies usually eat often in a 24-hour period and should gain about 1 ounce a day in the first month of life. It can be hard to judge this from home (even if you have a scale), so it's important to see your child's doctor regularly. Doctors can check for problems at regular well-child checkups, so it's important to keep these appointments.
When to Call the Doctor
If you notice a drop in weight gain or your baby doesn't seem to have a normal appetite, call your doctor. Also call about any major change in eating patterns. Toddlers and older kids may have days and sometimes weeks when they show little interest in eating, but that shouldn't happen in infants.
If you have trouble feeding your baby, your doctor can help. When a child doesn't readily eat, parents can become frustrated and feel they're doing something wrong. That can make the problem worse, causing stress for you and your baby. Instead, get help for both of you by talking to your doctor.