"How tall will my child be?" is a common question heard by pediatricians. Every parent, of course, hopes that their child will be above the 50th percentile for height.

When parents fear that their child will be short, I am frequently asked if there is treatment for short stature.

Nancie MacIver, MD, PhD, of Duke Pediatrics Division of Endocrinology, helps us to understand what is involved in making that assessment and who might profit from treatment.

--Dennis Clements, MD, PhD

Nancie MacIver, MD, PhD

Short stature is one of the most common reasons for referral to a pediatric endocrinologist. It is our job to decide whether there is a medical reason for the child’s short stature, and to provide referral, guidance, or treatment as indicated.

Evaluation

The first step in evaluation of a child with short stature is to review the medical and family history with the child’s parents or caregivers. This should include review of growth patterns since birth and consideration of any past or present medical problems the child may have.

In addition, the heights of immediate family members, particularly those of the parents, are important in the evaluation of a short child.

Physiologic Causes

There are two “physiologic” causes of short stature that are commonly encountered in our clinic. Physiologic causes are those not associated with any disease or illness.

The first is familial short stature. Simply stated, if a child’s parents are short, the child is likely to be short as well, because height is an inherited trait.

The second common physiologic cause is constitutional delay, a.k.a. the “late bloomer.”  Children with constitutional delay will usually enter puberty later than their peers, and have a delay in the onset of their pubertal growth spurt. However, these children will eventually catch up to their peers and grow to a normal adult height.

Hormonal Causes

Once the physiologic causes have been excluded, there are several hormonal causes of short stature that need to be considered when evaluating a short child. These include:

• Disorders of growth hormone secretion or action
• Deficiency of thyroid hormone
• Abnormal regulation of bone mineralization and calcium regulation
• Excess production or intake of corticosteroids, which results in a disorder called Cushing’s syndrome

In addition, abnormalities of the pituitary gland may result in multiple hormone deficiencies related to growth, and can include growth hormone, thyroid hormone, corticosteroids, and the sex hormones which regulate puberty.

Other Causes

There are several genetic syndromes that are associated with short stature, and should be considered in diagnosing the short child. Examples of these include Down syndrome, Turner syndrome, Noonan syndrome, and achondroplasia. Oftentimes, other clinical features are present which will indicate the possibility of one of these or other genetic disorders.

Poor growth and subsequent short stature can be a result of insufficient intake of calories. This may occur with dietary deficiencies, and sometimes from malnutrition or neglect. It can also occur with any disorder causing poor absorption of calories, such as celiac disease or cystic fibrosis.

An increase in utilization of calories may occur in inflammatory disorders, chronic diseases of the liver or kidney, or cancer.  Furthermore, a history of fetal growth restriction is not uncommon in children with short stature.

Diagnosis

Children presenting to their doctor with short stature may need laboratory testing to aid in diagnosis and to guide management decisions. This usually includes blood tests and almost always includes an x-ray of the hand and wrist, which is used to identify the child’s bone age.

A bone age is a measure of the maturity of the growth plates which are present in every joint. As children grow, their growth plates change size and shape, and when the growth plates have reached full maturity, growth is completed.

We can estimate bone age by comparing the child’s bone development in the growth plates of the hand and wrist to well-established standards. In many cases of short stature, the bone age may be delayed, particularly in the “late bloomer” with constitutional delay, but also in some of the hormonal and chronic illnesses listed above.

Treatment for Short Stature

Treatment for short stature may be useful for several of the above diagnoses. Effective treatment needs to be tailored to the cause of short stature. We often see children in our clinic who are interested in receiving growth hormone.

Growth hormone can be helpful in accelerating linear growth in some of the above-mentioned disorders, but is not a catch-all treatment, and is not effective for every cause. It cannot be used to treat short stature in a child who has already reached full bone development.

It is important to remember that growth hormone is a daily subcutaneous injection, which, like all medications, can be associated with serious side effects. Careful consideration of the risks and benefits associated with growth hormone must be undertaken by the patient, parents, and physician prior to its use.

Conclusions

Overall, short stature is a common problem seen in children referred to the pediatric endocrinologist, but has a wide range of causes. Your doctor will need to consider many different factors in diagnosing the cause, and will tailor treatment accordingly.

Not all children seen with short stature will either need treatment, nor benefit from it. However, in some children, treatment can be very effective and helpful in aiding the child with short stature to reach an appropriate adult height.

-- Nancie MacIver, MD, PhD, is a medical instructor with Duke Pediatrics Division of Endocrinology.

-- Dennis Clements, MD, PhD, is the chief of primary care pediatrics at Duke Children's Hospital.