What Is Precocious Puberty?
Precocious puberty, also known as early puberty, is when a child's body starts to go through the change into an adult body too soon. Puberty starts on average in girls between ages 8 and 13 and in boys between ages 9 and 14.
Girls who show clear signs of puberty and its progression before age 8 and boys before age 9 are considered precocious. It affects about 1 out of 5,000 children.
Many experts say that on average, puberty is starting earlier in the U.S. than it did in the past. The average age when girls get their first period has stayed roughly the same. But studies suggest that early signs—like breast development—are happening a year earlier than they did decades ago.
Precocious Puberty Types
There are two types of precocious puberty:
Central precocious puberty
This type is more common. It's just like normal puberty, but it happens early. The pituitary gland starts making hormones called gonadotropins. These hormones cause the testicles or ovaries to make other hormones: testosterone or estrogen. These sex hormones cause the changes of puberty, like breast development in girls.
Peripheral precocious puberty
This is also called precocious pseudopuberty and is less common. The hormones estrogen and testosterone trigger the symptoms. But the brain and pituitary gland aren't involved. It's usually a local problem with the ovaries, testicles, or adrenal glands.
Precocious Puberty Symptoms
The signs of early puberty and puberty are usually the same. It's the timing that's different. Signs include:
- Breasts start to grow (often the first sign)
- Menstruation (typically not until 2-3 years after the earlier symptoms start)
- Facial hair begins to appear
- Testicles, penis, and scrotum start to grow
- Voice deepening (this is usually a late sign of puberty)
- May have spontaneous erections or ejaculation
Girls and boys
- Rapid height growth
- Adult body odor
- Underarm and pubic hair
There are other conditions that might look like early puberty to parents—and sometimes even to pediatricians—but aren't:
- Premature thelarche is when a girl's breasts start to grow at a young age. It often affects girls who are just a few years old. While troubling for parents, it gets better on its own and isn't early puberty. It doesn't require treatment, but you should still take your child to a doctor to get their input.
- Premature pubarche is when pubic or underarm hair starts to grow at an early age. It can result from premature adrenarche, when the adrenal glands start releasing hormones early. Again, while it might seem alarming, it generally isn't a problem. It's also not an early sign of puberty. But because it may represent the first sign of an unusual and heavy release of adrenal hormones, your child should see a doctor.
Precocious Puberty Causes
There are a number of reasons why kids may go through early puberty, which differ depending on the type.
Central precocious puberty causes
Most of the time, experts don't know what causes central precocious puberty, particularly in girls.
Rarely, it can be triggered by another medical problem, such as:
- Tumors and other growths, which are often noncancerous (benign)
- Brain injury, either from surgery or a blow to the head, that affects hormonal balances
- Genetic conditions
- Seriously underactive thyroid
Peripheral precocious puberty causes
Usually, an underlying medical condition brings on puberty symptoms in these cases. Possibilities include:
- Tumors in the adrenal glands, ovaries, or testes
- Genetic conditions
- Exposure to products containing estrogen or testosterone
Precocious Puberty Risk Factors
While they aren't necessarily causes, a number of things are linked to early puberty. They include:
- Gender. Girls are 10 times as likely to have central precocious puberty as boys.
- Genetics. If precocious puberty is caused by a genetic problem, a child's parent or sibling may have it also.
- Race. Researchers don't know why, but on average, Black girls seem to start puberty about a year earlier than White girls.
- International adoption. One study showed that kids who are adopted outside the U.S. are 10-20 times more likely to develop precocious puberty. Experts aren't sure why, but the uncertainty of the exact ages of the adopted children might affect the study results.
- Obesity. A number of studies have shown a link between obesity in young girls and an increased risk of precocious puberty. But researchers don't know how direct the tie is. Obesity doesn't seem to be connected to early puberty in boys.
Precocious Puberty Diagnosis
To figure out if your child has precocious puberty, your doctor may:
- Go over their medical history
- Do a physical exam
- Do a blood test to check their hormone levels
- X-ray their hands and wrists to look at bone age; this tells them if the bones are growing too quickly
If the doctor sees signs of precocious puberty, they'll also run a test to see what kind it is. It's called a gonadotropin-releasing hormone (GnRH) stimulation test. The doctor gives your child a shot of these hormones, then takes a series of blood samples over a period to check their hormone response. If other hormones rise, that's a sign of central precocious puberty. If levels of other hormones stay the same, that's a sign of peripheral precocious puberty.
Your kid may get more tests to see what may be causing their condition. That can include:
- An MRI to look for brain issues
- Blood tests for thyroid function
- An ultrasound to look for a tumor
Questions for the doctor
You'll need to work with your child's doctor to decide what to do next. These questions can help get the conversation started.
- Which tests will you use to determine if my child has precocious puberty?
- Do you see any signs to suggest this is caused by a tumor or some other medical condition?
- What options are available to treat this condition?
- What are the side effects of treatment?
- How long do you recommend my child stay on this treatment?
- How will I know if the treatment is working or not working?
- What local services are available to help me support my child's emotional well-being?
- What if we don't treat it?
Precocious Puberty Treatment
Your child may be referred to a specialist called a pediatric endocrinologist for treatment. The treatment approach will depend on what's causing your child's precocious puberty.
- Watchful waiting. In many cases, your doctor won't be able to find a cause. They may suggest watching your kid for a few months.
- GnRH analogue therapy. If your child has central precocious puberty and no other conditions, the doctor may suggest GnRH analogue therapy. This is a medication your child gets once a month in a shot, until they reach the normal age for puberty. It stops sexual development while they take it.
- Histrelin implant (Vantas). Your child would need a minor surgery to get this implant. The doctor puts it under the skin of the inside part of their upper arm. It also delays development but doesn't require monthly shots. The implant lasts a year.
- Treatment of another condition. If your kid has a condition that's causing precocious puberty, treating that will usually stop it.
Precocious Puberty Complications
For kids, early puberty can cause physical and emotional problems. They include:
- Short stature. While kids with precocious puberty are often tall for their age, some wind up short as adults. Why? Once puberty is over, growth stops. Because precocious puberty ends earlier than normal puberty, these kids stop growing at an earlier age. The result may be a shorter height than they would have otherwise had.
- Behavior problems. Some studies show a link between early puberty and behavior problems, particularly in kids with developmental delays. But other experts say the proof is weak.
- Stress. Even when it's happening to average 12-year-olds, puberty can be a confusing time. It can be all the more stressful for younger kids with early puberty.
- Other risks. Some studies show a link between early puberty in girls and a slightly increased risk of breast cancer later in life. But the evidence isn't clear.
Keep an eye out for signs your child is struggling emotionally. This can include things like:
- A drop in their grades
- Other problems at school
- Avoiding social situations
- Loss of interest in things they usually enjoy
Tips for Parents
As a parent, it's easy to worry about early puberty. While you should take any signs seriously, keep in mind:
- Symptoms that might seem like early puberty are often unrelated and clear up on their own.
- When treatment is necessary, it usually works well.
- Most kids with signs of early puberty do fine, medically, psychologically, and socially.
How to Support Your Child
Most kids want to fit in. Developing early could make your child feel self-conscious. Other people may expect more maturity because they think your kid is older than they are.
These challenges plus the emotional changes from extra hormones can be a lot for them to deal with.
How can you help?
Explain what's happening in their body in simple terms.
Keep the lines of communication open. Encourage them to talk freely about their feelings.
Treat them appropriately for their age.
Watch out for teasing.
Do what you can to boost their self-esteem. Focus your praise on grades or activities rather than appearance.
Counseling or a support group may also help. Ask your child's doctor for a referral or other resources.