|Parents are often concerned about their children's weight, especially if they seem to be smaller than other children that are the same age. While there are many medical causes for being small and having poor weight gain, including inadequate nutrition, metabolic diseases, gastroesophageal reflux, parasite infestations, hyperthyroidism, and many chronic medical conditions, including congenital heart disease, renal failure, etc., it is often difficult to find a reason for a child's poor growth.
Failure to thrive is a term commonly used to describe younger children who aren't gaining weight normally. Children with failure to thrive usually have a weight that is below the 3rd or 5th percentile for their age and a declining growth velocity (meaning they are not gaining weight as expected) and/or a shift downward in their growth percentiles, crossing two or more percentiles on their growth charts.
If your child is just below the 3rd or 5th percentile for his weight, but he has been gaining weight normally and has a growth curve that runs parallel to the 3rd or 5th percentile and he has no other symptoms, then he probably has a normal weight. Your Pediatrician may just want to follow his growth and development at his normal well child checkups. Children with failure to thrive usually have a growth curve that over time is moving further away from the 3rd or 5th percentile or is becoming flat.
Children normally grow at a rate of about 30 g (1 ounce)/day in early infancy (birth to 3 months) and this then slows to about 20 g/day from 3-6 months and to only 12-15 g/day in later infancy (6 - 12 months). Older children grow even more slowly, with toddlers (1-3 years) growing, at about 8 g/day, and preschool age children at about 6g/day.
Many children between the ages of 6 and 18 months move up or down on their growth percentiles, but by 24 months, most children follow their growth curve and stay on the same percentile or growth channel. Still, it is usually concerning if any child, even those under 18 months, crosses more than two major percentiles downward, for example, going from the 80th percentile to the 40th (crossing the 75th and 50th percentiles), especially if he continues to have poor growth.
Among the influences on a child's growth is his overall genetic potential for growth, which can be determined from the height of his parents, his nutritional status, and the presence of any chronic medical problems.
It is also important to look at a child's length, in relation to his weight. Weight for length measurements can also be plotted on a growth curve and can help to determine a child's fat stores. A child's skin fold thickness, which can be determined by measuring their mid upper arm circumference is another measure of subcutaneous fat stores and malnutrition. Also, a child's head circumference should be measured and followed.
There are many causes of failure to thrive. Among the ways to categorize the different conditions that cause failure to thrive and poor weight gain is to group them into conditions that cause a decreased intake of calories or an increased loss of calories. Children may also have failure to thrive from having an increased requirement for calories, such as from having a chronic infection, hyperthyroidism, congenital heart disease or chronic lung problems.
Among the conditions that can cause your child to have a diet that doesn't provide enough calories for normal growth (decreased intake of calories) include:
- anorexia or refusal to eat from chronic medical problems, such as renal disease, cancer, congenital heart disease, metabolic disorders, liver disease, HIV infection, or gastroesophageal reflux with esophagitis.
- having a restrictive or fad diet
- preparing formula improperly
- poor milk supply for breastfeeding moms
- physical abnormalities that cause difficulty swallowing (dysphagia), such as neurological disorders including cerebral palsy, trauma to the mouth, congenital abnormalities, or disorders with motility or movement of the uppger gastrointestinal tract (such as achalasia).
- poverty can lead to inadaquate access to food. If you need assistance ask about getting help from WIC or other government programs.
There are many conditions that can cause an increased loss of calories including:
- illnesses that can cause persistent vomiting (such as pyloric stenosis, intestinal obstructions (such as a volvulus), or a brain tumor).
- conditions associated with malabsorption, usually with diarrhea which can be foul smelling and oily, such as from cystic fibrosis, allergies, celiac disease, inflammatory bowel disease, parasite infestations or other intestinal infections.
- diabetes mellitus (usually includes weight loss, increased urination (polyuria) and increased thirst and drinking (polydipsia) and other metabolic conditions..
Children with failure to thrive should have a full evaluation by their Pediatrician. This will include a detailed nutritional history, including amounts and types of foods that your child eats and drinks (including the amount of juice he drinks), a description of associated symptoms (especially vomiting, diarrhea, or fever), a physical exam and a review of prior growth records to evaluate your child's rate of growth. The rate of growth is among the most important things that will be assessed. If your child is below the 3rd or 5th percentile, but is growing normally with a growth curve that is parallel to the 3rd or 5th percentile, and he has a healthy diet and no associated symptoms, then your Pediatrician may just observe his weight gain over the next few months.
If your child is not growing well, with a growth curve that is flat, moving downward across more than 2 major percentile or is moving further away from the 3rd or 5th percentile, then your Pediatrician may do further testing. This testing will usually include a complete blood count (screens for anemia or low blood counts), erythrocyte sedimentation rate (ESR which can be elevated with inflammation or infections), a urinalysis and urine culture (can show evidence of a renal tubular acidosis or chronic renal disease or infections), blood chemistry tests (includes electrolytes, BUN and creatinine (renal function tests), liver function tests, and albumin, protein and mineral levels (calcium and magnesium)), stool tests for fat, culture and parasites, a sweat chloride test (for cystic fibrosis), an HIV test, PPD (for tuberculosis) and a blood lead level.
Other testing will depend on a child's specific symptoms, and may include (but are not limited to) an upper gastrointestinal series for persistent vomiting, serum glucose to look for diabetes, thyroid function tests, blood and urine tests to look for metabolic problems, and upper or lower gastrointestinal endoscopy for persistent vomiting and/or chronic diarrhea.
Treatment of failure to thrive is usually carried out with a team approach, with your Pediatrician, a Pediatric nutritionist, and appropriate specialist referrals as indicated. There are many Pediatric specialists that can evaluate a child with failure to thrive, depending on your Pediatrician's suspicion of the cause. Often, especially if they have gastrointestinal symptoms, such as vomiting or chronic diarrhea, a Pediatric Gastroenterologist will evaluate your child.
Treatment depends on the underlying cause. If no medical reason is found for your child's failure to thrive, then often treatment will consist of nutritional therapy to see if your child will gain weight if given an adequate amount of calories. This may be done in the hospital over a few weeks or it may begin as an outpatient. Feedings may be given orally, by a nasogastric tube (usually as overnight slow drip feedings) if your child just won't eat enough calories, or by an intravenous (IV) line as total parenteral nutrition (TPN) if your child is not able to digest and absorb oral feedings.
To make mealtimes easier and maximize the chances that your child will eat, you can:
- avoid trying to force or bribe your child to eat. Turning meals into a power struggle usually doesn't help and may make your child more resistant to eating.
- Have a schedule for meals and snacks, which should include 3 meals and 2-3 snacks each day of high calorie foods with lots of nutrients (see below).
- Allow your child to feed himself, especially finger foods, as much as possible.
- Only offer liquids, especially juice, after the meal.
- Avoid large amounts of juices, sodas, or water. Offer milk or formula, which have more calories and protein, instead.
A Pediatric nutritionist can also suggest ways that you can provide your child with more calories by offering high calorie foods that are high in protein with lots of nutrients, especially since he will need additional calories to help him catch-up with his growth, including (disclaimer: only use these suggestions for increasing the calories that you are giving your child under the guidance of your Pediatrician or a Pediatric nutritionist):
- avoid junk foods, such as candy, which may have calories, but are usually low in protein.
- for younger children, under the direction of your Pediatrician or a nutritionist, your infant's formula can be concentrated to provide more than the regular 20 calories/ounce.
- for older children, over 12 months of age, instead of milk, you can offer Pediasure, which has 30 calories/ounce (vs 20 calories/ounce for whole milk) 2-3 times a day.
- or mix whole milk with a packet of instant breakfast powder (adds 130 calories) or dry milk powder (adds 33 calories per tablespoon) to increase calories.
- when baking and cooking, substitute whole milk, half and half, evaporated milk or condensed milk mixed with dry milk powder for water or milk.
- for high calorie snacks, offer milk shakes made with a cup of whole milk, a packet of instant breakfast powder and a cup of ice cream blended together (can provide over 400 calories).
- pudding can also provide a lot of calories if you add 1/2 cup of dry milk powder to the milk and instant pudding mix.
- add cheese as a topping for sandwiches, vegetables, etc.
- use peanut butter (about 100 calories/tablespoon) as a snack and as a topping for vegetables, crackers, and fruits or blended with milk, ice cream or yogurt
- make a high calorie fruit snack using fruits canned in heavy syrup, add sugar or yogurt to fresh fruit or add a packet of instant breakfast powder to strained fruits.
- make high calorie jello by substituting fruit juice for water in its preparation
- serve meats and breads with added butter, margarine, gravy or sauces
- serve fried foods, such as fish and chicken and add breading or flour before cooking
Your child may also need to see an occupational therapist or speech therapist if he has a food aversion or difficulty swallowing.
Psychosocial factors can also cause a child to have failure to thrive. This may involve behavioral factors of the child that make him difficult to handle and feed, or psychological factors in the parents and their relationship with their child.
Among the factors that will make your Pediatrician suspicious that there is a medical reason for your child's low weight and that a further evaluation is necessary include:
- if your child's plotted weight on a growth curve is crossing percentiles downward, especially after he is 18-24 months of age or if it has crossed more than two major percentiles. For example, if his height had been following along at the 70th percentile and has now moved down to the 20th (crossing the 50th and 25th percentiles).
- poor appetite and/or poor nutrition
- chronic abdominal pain and diarrhea
- persistent fever
- weight loss
- chronic worsening headaches and/or vomiting
- a growth curve very much below the 3rd percentile
- a height that is much below that predicted by mid-parental height
- if your child's short stature is disproportionate or he has other dysmorphic signs which can indicate a chromosomal disorder.
Growth Disorder Resources:
- The Magic Foundation: "Major Aspects of Growth In Children for Children's Growth and Related Adult Disorders," a nonprofit organization providing support and education regarding growth disorders in children and related adult disorders, including adult growth hormone deficiency.