Pediatrics for Parents

Short Stature and Development

Patricia G. Wheeler, MD and Ethan Balk, MD

"Short stature" is the term used to describe a child who is not as tall as his or her same age peers. From a medical perspective, there are a variety of causes of short stature in children:
•  Specific abnormalities of bone growth (often called skeletal dysplasias)
•  Growth hormone deficiency
•  Poor nutrition
•   Various chronic medical diseases
•  Inherited or genetic causes

We recently performed a systematic review of studies that examined children with short stature and their risk for disability. Short stature was defined as a height below the 5th percentile, or being shorter than 95% of children his or her age and sex. The goal was to examine the association between short stature in children and a wide range of physical, intellectual, and emotional disabilities, including how activities of daily living may be affected.

However, because current research of the effect of short stature has been done only for a narrow range of children's abilities, we focused on four measures of children's abilities: academic achievement, intelligence, teacher-evaluated behavior, and visual-motor skills. We looked at children with short stature due to conditions such as growth hormone deficiency or isolated short stature (no medically determined cause of the short stature). We did not include children with short stature due to either bone diseases or other medical conditions such as cancer or malnutrition.

In general, children with short stature had intelligence and academic achievement within the normal range for their age, but they typically scored lower than their average height peers. One possible explanation for this is that some children with apparently isolated short stature may have subtle underlying genetic or medical conditions that may impact on their intelligence or academic functioning. None of the studies showed that the children's short stature caused the lower intelligence or poorer academic achievement.

Teacher-evaluation is considered to be a more objective measure of behavior than evaluations by the children's parents or guardians. Overall, the teachers found no significant difference between children with short stature and their peers of average height.

Visual-motor skill tests are designed to estimate a child's ability to integrate or coordinate what they perceive with their motor skills. This is generally done by having the children copy a series of designs. Short children are significantly more likely to have a reduction in visual-motor skills compared to standardized norms. However, this result may be biased because only children who were followed in clinics specializing in short stature were evaluated. It is possible that some of the children were referred to the clinics specifically because they had some disabilities. In addition, the children's deficits may be overstated because they were not compared to comparable control children.

Overall, the evidence suggests that short stature may be associated with a small, though possibly not significant, decrease in intelligence and academic achievement, a delay in visual-motor skills, and little to no worsening of behavior problems. Limited data suggest that the treatment of children with short stature with growth hormone therapy does not improve their functioning.

Growth hormone treatment involves daily subcutaneous injections of laboratory made growth hormone, typically for several years of more. Growth hormone therapy is expensive with average costs that can easily reach $10,000 a year. This treatment is not covered by all insurance plans.

The potential side effects of growth hormone therapy include idiopathic intracranial hypertension (increased pressure inside the skull), slipped capital femoral epiphyses (problems with the hip) and impaired glucose tolerance, a sign of early diabetes mellitus.

In general, most doctors believe that growth hormone treatment is most appropriate for those children who are so short that they are limited in their ability to function. For example, the child is too short to climb on a bus or to use a school restroom. This treatment is also indicated for children whose estimated adult height would be less than four feet ten inches.

The main intent of growth hormone therapy is to help a child function in the real world not necessarily to make the child as tall as his peers.

Patricia Wheeler, MD is a clinical geneticist and pediatrician at Nemours Children's Clinic in Orlando, Florida. Dr. Ethan Balk is an internist who specializes in systematic reviews at Tufts-New England Medical Center in Boston, MA.