Growth hormone is a substance produced by the body that is integral to a child’s development. Secreted from the pea-sized pituitary gland at the base of the brain, its primary function is to stimulate the growth of bones and other tissues. It also regulates the body’s metabolism, including how it builds muscle and uses fat, helping to maintain a healthy body composition.
Childhood growth hormone deficiency, or GHD, is a condition where the pituitary gland fails to produce a sufficient amount of growth hormone. This can be a partial or total deficiency and may be present from birth or develop later. GHD affects a child’s ability to grow at a normal rate but does not impact their intelligence.
Identifying Potential Deficiency in a Child
A primary indicator of GHD is a slow or flat rate of growth. A doctor may observe this during routine check-ups by tracking measurements on a growth chart, as a growth rate of less than 2 inches per year for children between ages 4 and 6 raises concern. This persistent slow growth is the most apparent sign that prompts further investigation.
Beyond slow growth, children with GHD may have a younger-looking face than their peers, with a prominent forehead and an underdeveloped bridge of the nose. Another common sign is a chubby body build with increased fat around the abdomen. This is related to the hormone’s role in metabolism.
GHD can also affect the timing of developmental milestones, such as impairing hair growth or delaying puberty. While these signs can be subtle, their combination with a documented slow growth rate provides a clearer picture. The pattern of these signs, rather than a single observation, points toward a possible deficiency.
Causes of Growth Hormone Deficiency
Some children are born with the condition, known as congenital GHD. This may stem from genetic factors or issues with the development of the brain and pituitary gland before birth. In some cases, the physical structure of the pituitary gland or hypothalamus is abnormal.
A deficiency can also be acquired, developing after birth due to an external event or medical issue. Acquired GHD can occur if the pituitary gland or hypothalamus is damaged from a serious head injury, a brain tumor, or an infection like meningitis. Radiation therapy to the head is another cause of acquired GHD.
In a majority of cases, a specific cause for the deficiency cannot be identified, which is referred to as idiopathic GHD. For these children, the pituitary gland fails to produce enough growth hormone without any clear structural problem or injury. This diagnosis is reached after other potential causes have been ruled out.
The Diagnostic Process
The diagnostic process begins with a review of the child’s growth history. A pediatric specialist analyzes measurements on a growth chart to confirm a slow growth velocity, such as a pattern that crosses downward through percentile lines over time. This step helps differentiate a hormonal issue from a temporary lag in growth.
If the growth pattern is concerning, the next step is a series of blood tests. Because growth hormone levels fluctuate, doctors instead measure proteins like Insulin-like Growth Factor 1 (IGF-1) and Insulin-like Growth Factor Binding Protein 3 (IGFBP-3). The liver produces these in response to growth hormone, so their levels provide a more stable indicator of the body’s growth hormone activity.
To assess skeletal maturity, a doctor will order a “bone age” X-ray of the child’s left hand and wrist. This image allows the doctor to compare the child’s bone development to standardized images for their chronological age. In children with GHD, skeletal maturation is often delayed, with a bone age two or more years behind their actual age.
The most definitive diagnostic tool is a growth hormone stimulation test. Because the body releases the hormone in short bursts, a single random blood sample is not sufficient for diagnosis. During the test, the child is given medication to trigger the pituitary gland to release growth hormone, and staff draw several blood samples over a few hours to measure the response.
An insufficient response during this test confirms the diagnosis of GHD. Following this, an MRI of the brain may be performed. This imaging visualizes the pituitary gland and checks for any structural abnormalities or tumors that could be the cause.
Treatment and Management
Once a child is diagnosed with GHD, the standard treatment is growth hormone therapy. This involves replacing the missing hormone with a synthetic, biologically identical version. The therapy consists of daily injections administered at home, usually in the evening to mimic the body’s natural cycle of hormone release.
Modern delivery methods have made the process simpler for families. Most children use an injector pen, which is designed for ease of use with a simple push-button mechanism and fine needles to minimize discomfort. Parents and children are taught how to perform the injection, making it a manageable part of their daily routine.
The goals of treatment extend beyond increasing height. While achieving a normal adult height is a primary objective, the therapy also improves body composition by increasing muscle mass and decreasing fat. It also supports healthy bone density, which reduces the risk of osteoporosis later in life. A pediatric endocrinologist monitors the treatment, adjusting the dosage as the child grows, until the bone growth plates close.
Long-Term Outlook
With consistent treatment, the long-term outlook for children with GHD is very positive. Most children who receive therapy reach an adult height within the normal range for their family. Early diagnosis and treatment help a child catch up on growth and prevent long-term health issues associated with untreated GHD, such as decreased bone density and metabolic complications. Regular follow-ups with a pediatric endocrinologist ensure the treatment is optimized throughout the growth years, helping the child transition into a healthy adulthood.