Early or Late Puberty
Jun 23, 2021
Precocious puberty is when a child's body begins changing into that of an adult too soon. Precocious puberty signs and symptoms include development of the following before age 8 in girls and before age 9 in boys,
- Pubic or underarm hair
- Rapid growth
- Adult body odor
- Breast growth and first period in girls
- Enlarged testicles and penis, facial hair and deepening voice in boys
What causes precocious puberty?
If you suspect your child is going through puberty early talk with your doctor. It may be caused by tumors or growths on the ovaries, adrenal glands, pituitary gland, or brain. Other causes may include central nervous system problems, family history of the disease, or certain rare genetic syndromes. In many cases, no cause can be found for the disorder. There are two types of precocious puberty:
- Gonadotropin-dependent. This is also known as central precocious puberty. This is the most common type of precocious puberty. Most girls and half of boys with precocious puberty have this type. The puberty is started by early secretion of hormones called gonadotropins. Gonadotropins include luteinizing hormone (LH) and follicle stimulation hormone (FSH). In girls, precocious puberty may be caused by the early maturity of the hypothalamus, pituitary glands, and ovaries. But in most cases, no cause can be found.
- Gonadotropin-independent. This is a form of precocious puberty that is not started by the early release of gonadotropins. Instead it’s caused by early secretion of high levels of sex hormones. These include the male androgens and female estrogens.
Factors that increase a child's risk of precocious puberty include:
- Being a girl. Girls are much more likely to develop precocious puberty.
- Being African-American. Precocious puberty appears to affect African-Americans more often than children of other races.
- Being obese. Children who are significantly overweight have a higher risk of developing precocious puberty.
- Being exposed to sex hormones. Coming in contact with an estrogen or testosterone cream or ointment, or other substances that contain these hormones (such as an adult's medication or dietary supplements), can increase your child's risk of developing precocious puberty. Ingesting animal products that have been given growth hormones may also be a culprit.
- Having other medical conditions. Precocious puberty may be a complication of McCune-Albright syndrome or congenital adrenal hyperplasia — conditions that involve abnormal production of the male hormones (androgens). In rare cases, precocious puberty may also be associated with hypothyroidism.
- Having received radiation therapy of the central nervous system. Radiation treatment for tumors, leukemia or other conditions can increase the risk of precocious puberty.
- Exposure to hormone disrupting chemicals. Recent research is looking at how some chemicals released from plastics and other products may disrupt the production and uptake of hormones in the body.
Some of the risk factors for precocious puberty, such as sex and race, can't be avoided. But, there are things you can do to reduce your child's chances of developing precocious puberty, including:
- Keeping your child away from external sources of estrogen and testosterone — such as prescription medications for adults in the house or dietary supplements containing estrogen or testosterone
- Encouraging your child to maintain a healthy weight
To diagnose precocious puberty, the doctor will:
- Review your child's and your family's medical history
- Do a physical exam
- Run blood tests to measure hormone levels
X-rays of your child's hand and wrist also are important for diagnosing precocious puberty. These X-rays can help the doctor determine your child's bone age, which shows if the bones are growing too quickly.
It's not always clear what causes delayed puberty. It may just be a tendency that runs in your family. Delayed puberty is defined when:
- Boys have no signs of testicular development by 14 years of age. Boys can start puberty at a wide range of ages, with 95% starting between the ages of 9 and 14. The earliest sign of puberty in boys is enlargement of the testicles, followed by growth of the penis and pubic hair.
- Girls have not started to develop breasts by 13 years of age, or they have developed breasts but their periods have not started by 15
Some girls with delayed puberty are simply late maturers, but once they start, puberty will progress normally. This is called constitutional delayed puberty and is more common in boys than girls. Often, this is something that is inherited from the parents, so it is more likely to occur if the mother started her periods after age 14 (the average is about 12 ½) or if the father was a "late bloomer." Delayed puberty is generally more common in boys.
Occasionally it can be caused by:
- a long-term illness, such as cystic fibrosis, diabetes or kidney disease. Chronic illnesses in which body fat is often decreased.
- malnutrition, possibly from an eating disorder or a condition such as cystic fibrosis or coeliac disease. It can also be seen in girls with anorexia nervosa, who engage in extreme dieting or binging and purging
- a problem with the ovaries, testes, thyroid gland or pituitary gland
- a disorder of sexual development, such as androgen insensitivity syndrome
- a genetic condition, such as Kallman syndrome and Klinefelter syndrome
- decreased body fat is a major cause of pubertal delay in girls. It can be seen in girls who are very athletic, particularly in gymnasts, ballet dancers, and competitive swimmers
Tests and treatments for delayed puberty
Your GP may refer you to a specialist if they think there could be an underlying cause of delayed puberty that needs to be investigated.
Tests that may be carried out include a blood test to check hormone levels, a hand X-ray to help determine likely adult height, and an ultrasound or MRI scan to check for problems with glands or organs.
For girls an endocrinologist will order blood tests to measure levels of LH, FSH, and estradiol and, in some cases, other tests. Very high levels of LH and FSH will indicate that the ovaries are not working properly, and the pituitary is trying to stimulate them to work harder. If the cause of the ovarian insufficiency is not clear, a chromosome study or karyotype will be done to see if all or some cells are missing all or part of an X chromosome.
If the LH, FSH, and estradiol are all low, the problem could be either decreased body fat (if one of the risk factors listed above is present) or a permanent deficiency of LH and FSH. Other tests may be ordered if deficiency of multiple pituitary hormones is suspected, and on occasions, a brain MRI may be helpful. A hand X-ray for a bone age is often done, which is typically delayed by 2 or more years, which means that there is still additional time to grow.
How is delayed puberty in girls treated?
In girls with constitutional delayed puberty, breast development will eventually start on its own. Giving estrogens for 4-6 months is sometimes used to help get things started sooner.
- For girls with delayed puberty and decreased body fat: Sometimes eating more and gaining weight will help get puberty started.
- For girls with primary ovarian insufficiency or a permanent deficiency of gonadotropins: Long-term estrogen replacement is needed and can be given either in the form of a daily tablet of estradiol or as a patch that needs to be applied to the skin twice a week. Doctors usually start on a low dose and often increase the dose about every 6 months. After 12-18 months, it is typical to start a second hormone called a progestin (for example, Provera) which will, after a few months, result in a period, usually within a day or two of stopping the progestin. You may ask your endocrinologist to discuss with you and your child what is known about your child's potential for fertility.
Delayed puberty can be treated by:
- treating any underlying cause
- using medication for a few months to increase hormone levels and trigger the start of puberty
Treatment with medication is usually recommended if the lack of development is causing problems, such as significant distress. I hope this basic information is helpful to know what to expect or where to start. Always talk with a doctor to have the proper tests and screenings done. You've got this!