This was written by David Segal, MD, PPG - Pediatric Specialties, Endocrinology.
Growth is an important function of childhood and adolescence, and poor growth may be a marker of an underlying problem. It’s crucial that parents and caregivers understand expected normal development and the red flags that could warrant further investigation.
How do we gauge expected normal growth?
Growth reference charts, like this one from the Centers for Disease Control and Prevention (CDC) have been compiled to cover the entire population of a country. The CDC example includes residents of the United States from all nationalities, races and cultures. Other growth charts may be more focused on a specific nationality or medical condition.
Reference charts create a visual representation of a statistical distribution of the population around an average for age and sex from birth to 20 years of age. It’s important to recognize that a person may be growing normally but not fall within the “normal” defined growth distribution defined by the chart. Conversely, someone can fall within the “normal” defined growth distribution but not be growing normally.
A growth disorder is usually considered when an individual is not following the normal distribution of growth, either in terms of absolute stature (standing height or lying length) or growth rate (number of inches per year).
What are factors that can cause a growth disorder in children?
There are a number of considerations and causes of growth that deviates from normal. The most common are variants of normal growth, such as familial short stature (short parents make short kids) and constitutional delay in growth and puberty (typical late bloomers).
Then there are other conditions that need to be actively investigated, such as systemic diseases (conditions affecting one or more organ systems), like chronic infections, malabsorption of nutrients, anemia, and lung and gut problems, to name a few. Physicians also consider endocrine disorders, the most common being hypothyroidism (under active thyroid), growth hormone deficiency and excessive steroid exposure (for treating asthma), as well as children born small for gestational age, genetic syndromes and idiopathic short stature (individuals who are short, but tests cannot find a cause).
What are the symptoms of growth disorders?
There are often no symptoms of growth disorders apart from those associated with the underlying causative condition. That’s why it’s important to measure children accurately and plot them on a growth curve to detect deviations from expected growth.
How are growth disorders diagnosed?
Growth disorders are diagnosed after detecting poor growth. This is done by accurately measuring the patient’s length (lying down) or height (standing up) and plotting it on a growth chart. The child’s height is compared to a predicted height for them based not only on the population normal, but also factoring in their genetics, done by estimating their target height based on their parents’ heights.
If a growth problem is suspected, the primary care provider can perform a targeted history and physical examination. If there are concerns that there is an underlying pathology it’s worthwhile for them to refer the child to a pediatric endocrinologist for further evaluation and testing. These specialists are familiar with the tests needed in these cases, which can be expensive and require specially timed or stimulated blood draws (growth hormone stimulation testing).
A common investigation providers use is a bone age x-ray of the left hand to assess the maturation of the growth plates and estimate future growth potential. Follow-up tests, such as MRI scans and genetic studies, may be necessary and ordered by the pediatric endocrinologist to confirm a diagnosis or exclude a specific pathology.
How are growth disorders treated?
Not all growth disorders need treatment! Sometimes, watchful waiting is all that’s required after various conditions have been ruled out. Other conditions require early diagnosis and intervention to maximize the final height outcome.
Synthetic growth hormone has been used to treat a number of conditions associated with short stature, even if it’s not directly caused by growth hormone deficiency. Growth hormone is injected once daily or once weekly for a period of years to boost growth rate until an acceptable final height is achieved. These treatments are most effective when taken as prescribed and for long periods, typically years.
One of the major barriers to accessing growth hormone is the limited number of conditions approved for growth hormone use, as well as obtaining insurance coverage for growth hormone even for approved indications due to the high cost of the treatment.
What are some tips for parents who have a child with a growth disorder?
Parents have a good sense of their child’s growth and some expectations of height relative to their peers, other siblings and family. If a parent develops concerns about their child, then they should raise them with their primary care provider.
Don’t wait for the pubertal growth spurt. It might not happen and then it could be too late to change the height outcome. Growing takes time, so the sooner a problem is detected and treated, the better the result.