Pediatric growth hormone deficiency (PGHD) is a genetic condition that affects your child’s physical development. Hormone replacement therapy can help promote growth, and a new injection now makes it easier to administer treatment.

The pituitary gland regulates growth, metabolism, and reproduction through hormone secretion. When the gland does not produce enough growth hormone (GH), a deficiency occurs, usually resulting in slow bone and tissue growth.

In children with PGHD, the most noticeable symptom is often slow height growth, or what is commonly known as short stature.

Treatments are available if your child has PGHD. They typically come in the form of hormone replacement therapy.

Treatment can begin immediately after diagnosis, starting with hormone injections of recombinant human growth hormone therapy.

Hormone injections for PGHD use recombinant human growth hormone (rhGH), a synthetic version of the growth hormone naturally produced by the pituitary gland.

Commonly known as somatropin, the drug comprises a manufactured protein that mimics natural growth hormones as closely as possible. As a result, it can stimulate both bone and tissue growth, promoting linear (height) growth.

rhGH can also positively affect metabolism. The treatment was first approved by the Food and Drug Administration (FDA) in 1985 and continues to be the standard first-line treatment for human growth hormone deficiency in children unless contraindicated.

Situations in which a doctor may discourage the use of growth hormone injections include:

  • an active malignant condition
  • a history of airway obstruction
  • sleep apnea
  • severe obesity

Subcutaneous injection is the method used to administer growth hormone. This means that a needle is used to deliver the drug into the fatty tissue just below the surface of the skin. It’s a shallow injection and is touted as nearly painless when delivered via automatic injection.

Subcutaneous injection devices for children use a special housing that resembles a pen. The press of a button delivers the medication through automatic injection. Older children ages 10 or above, can often learn how to give themselves growth hormone injections.

A child has the option to use various sites on the body for rhGH injection, including the tops or outsides of the thighs, the backs of the arms, the outer quadrant of the buttocks, and the sides of the abdomen. Most doctors recommend rotating the injection sites every time.

Treatment with human growth hormone is often long-term, continuing for a period of years. Throughout this time, doctors recommend giving a subcutaneous injection once per day.

Most commonly, healthcare professionals give the injection in the evening because children naturally release growth hormone during sleep. Giving the rhGH injection at bedtime, an hour or less before sleep, improves efficacy.

Over time, your child’s doctor may increase the dose. The dosage for somatropin is typically between 0.15 and 0.3 milligrams per day.

Appointments every 3 to 6 months are used to monitor height and adjust the dose if necessary.

Research has shown that growth hormone therapy improves both height velocity and final height in children with PGHD. Results often take a few months to appear, usually showing up 3 to 4 months after injections begin.

Growth resulting from rhGH therapy typically takes place in four stages:

  • initial phase (the first 2 to 3 years, also called the catchup phase)
  • childhood growth phase
  • pubertal phase
  • final phase (when your child attains or is almost at their adult height)

Studies have found that rhGH treatment in children with GH deficiency results in a height that is 3 to 4 centimeters (cm) less than the familial target height. Starting the therapy later in childhood and not allowing enough time for catchup growth before puberty can result in a greater difference from the familial target height.

Every child is different, so it’s important to note that not all respond well to growth hormone therapy.

Serious side effects from growth hormone therapy are rare. Potential side effects include:

  • muscle and joint aches
  • headaches
  • fluid retention
  • slippage of the hip joints and bones
  • insulin resistance
  • pain and rash at the injection site

One of the newest advancements in treating children with growth hormone deficiency is long-acting growth hormone (LAGH). Unlike traditional rhGH therapy, LAGH injections only need to be given once per week.

In 2023, the FDA approved somatrogon-ghla (NGENLA), a long-acting growth hormone injection for children ages 3 and over. Clinical studies found it had comparable safety and efficacy compared with somatropin. However, research into LAGH injections is still somewhat limited.

Sometimes, if rhGH is started too late, or a child has precocious (early) puberty, doctors may use drugs to suppress puberty in combination with growth hormone injections. Medical professionals use the term gonadotropin-releasing hormone analogs (GnRHa) to describe these types of medications.

Some studies found an additional 6 to 9 cm of height gained during the adult phase when patients received GnRHa with rhGH. However, research on this is still limited.

Daily injections of rhGH remain the most common treatment for pediatric growth hormone deficiency. However, long-acting growth hormone injections show promise and can reduce injection frequency from daily to weekly.

Starting growth hormone therapy earlier increases the chances that your child will reach near-average adult target height range. If untreated, PDGH can lead to short stature and a delayed onset of puberty.

Medical professionals will closely monitor the progress of growth hormone therapy in children throughout their treatment, as not all of them respond well to it.