Definition

Precocious puberty in girls is a condition where a girl's body begins changing into an adult body (puberty) too soon. When puberty starts before the age of 8 in girls, it is called precocious puberty.

Causes

Puberty begins when the brain starts producing a hormone called gonadotropin-releasing hormone (GnRH). When this hormone reaches the pituitary gland (a small, bean-shaped gland at the base of the brain), it stimulates the ovaries' production of estrogen. Estrogen is involved in the growth and development of female sexual characteristics.

The causes for this process starting earlier in some children can be categorized into central precocious or peripheral precocious puberty.

• Central Precocious Puberty. The causes of this type of precocious puberty are often not identifiable. In central precocious puberty, the puberty process starts too early, but the pattern and sequence of puberty are normal. Most children with this condition do not have an underlying medical problem or a clear reason for early puberty. In rare cases, central precocious puberty can be caused by: 
  • Tumors in the brain or spinal cord (central nervous system)
  • Congenital brain defects, such as hydrocephalus or benign tumors
  • Brain or spinal cord injuries
  • McCune-Albright syndrome, a rare genetic disorder affecting bones, skin pigmentation, and hormonal problems
  • Congenital adrenal hyperplasia, a group of genetic disorders involving abnormal hormone production by the adrenal glands
  • Hypothyroidism, a condition where the thyroid gland does not produce enough thyroid hormone

• Peripheral Precocious Puberty. Estrogen in a child's body causes this type of precocious puberty. Peripheral precocious puberty is less common and occurs without the involvement of the normal GnRH hormone that triggers the start of puberty. Causes of estrogen release into the body include disorders of the ovaries, adrenal glands, and pituitary gland. 

In girls, the following can cause peripheral precocious puberty:

• • Tumors in the adrenal gland or pituitary gland that release estrogen
  • McCune-Albright syndrome
  • Ovarian cysts
  • Ovarian tumors

Risk Factor

Factors that increase a child's risk for precocious puberty include:

• African-American ethnicity. Precocious puberty appears to occur more frequently in African-American children compared to other races.
• Significant overweight. Children who are significantly overweight have a higher risk of experiencing precocious puberty.
• Exposure to sex hormones. Contact with creams or ointments containing estrogen or other substances containing these hormones (such as adult medications or dietary supplements) can increase the risk of precocious puberty.
• Receiving radiation therapy to the central nervous system. Radiation therapy for tumors, leukemia, or other conditions can increase the risk of precocious puberty.

Symptoms

Signs and symptoms of precocious puberty include the following physical developments before the age of 8:

• Breast growth and the first menstrual period
• Pubic or underarm hair growth
• Rapid body growth
• Acne
• Adult body odor

Diagnosis

To diagnose precocious puberty, doctors will:

• Assess your child's and family’s health history
• Perform a physical examination
• Conduct blood tests to measure hormone levels

X-rays of your child's hand and wrist are also important for diagnosing precocious puberty. These X-rays can help doctors determine your child's bone age, which shows whether bones are growing too quickly.

Doctors will also determine the type of precocious puberty your child has. To do this, they will conduct a test called a GnRH stimulation test. In this test, doctors take a blood sample, give your child an injection containing the GnRH hormone, and then take additional blood samples at specific intervals to see how your child's hormones respond. In children with central precocious puberty, GnRH will cause hormone levels to rise. In children with peripheral precocious puberty, hormone levels will stay the same.

• Additional tests for central precocious puberty include:
  • MRI. A brain MRI is usually done for children with central precocious puberty to check for brain abnormalities causing early puberty.
  • Thyroid examination. Doctors may also check your child's thyroid if they show signs of thyroid dysfunction.

• Additional tests for peripheral precocious puberty may be needed to find the cause. For example, doctors may perform additional blood tests to check other hormone levels. In girls, doctors may also perform an ultrasound to check for ovarian cysts or tumors.

Management

Treatment for precocious puberty depends on the cause. However, in some cases, no identifiable cause is found. In such cases, your child may not require treatment depending on their age and how quickly puberty progresses. Doctors may monitor your child for a few months to observe their development.

• Treatment for Central Precocious Puberty.

Most children with central precocious puberty without a specific cause can be effectively treated with medication. This treatment, called GnRH analog therapy, usually involves injections that delay further development. Children will continue receiving this medication until they reach the normal age of puberty. On average, 16 months after stopping the medication, the puberty process will start again. Another treatment option is the histrelin implant, which lasts up to 1 year. This treatment is effective without pain and regular injections but requires minor surgical procedures. The implant is placed under the skin through an incision in the upper inner arm. After one year, the implant is removed and, if necessary, replaced with a new one.

• Treatment for Underlying Medical Conditions

If another medical condition causes precocious puberty, treatment for that condition is important to stop the progression of puberty. For example, if a child has a hormone-producing tumor causing precocious puberty, puberty will usually stop when the tumor is removed.

Complications

Possible complications of precocious puberty include:

• Short stature. Children with precocious puberty may grow quickly at first and look tall compared to their peers. However, because their bones mature faster than normal, they often stop growing sooner than usual. This can result in shorter than average height as adults. Early treatment for precocious puberty, especially when it occurs in very young children, can help them grow taller than they would without treatment.
• Social and emotional problems. Children who begin puberty much earlier than their peers may become very self-conscious about the changes happening in their bodies. This can affect their self-esteem and increase the risk of depression or substance abuse.

Prevention

Some risk factors for precocious puberty, such as race, cannot be avoided. However, you can reduce the likelihood of your child developing precocious puberty by:

• Ensuring your child is not exposed to external sources of estrogen, such as adult medications or dietary supplements containing estrogen
• Encouraging your child to maintain a healthy weight

When to See a Doctor?

Consult a doctor for an evaluation if your child shows any signs or symptoms of precocious puberty.

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