Delayed Puberty

ByAndrew Calabria, MD, The Children's Hospital of Philadelphia
Reviewed/Revised Apr 2024
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Delayed puberty is defined as absence of the start of sexual maturation at the expected time.

  • Most often, children simply develop later than their peers but ultimately develop normally.

  • Sometimes, delayed puberty is caused by chronic medical problems, hormonal disorders, radiation therapy or chemotherapy, disordered eating or excessive exercise, genetic disorders, tumors, and certain infections.

  • Typical symptoms include a lack of testicular enlargement in boys and a lack of breasts and menstrual periods in girls.

  • The diagnosis is based on the results of a physical examination, various laboratory tests, a bone age x-ray, genetic testing, and other imaging tests.

  • Treatment depends on the cause and may include hormone replacement therapy.

(See also Puberty in Boys and Puberty in Girls.)

The start of sexual maturation (puberty) takes place when the hypothalamus gland begins to secrete a chemical signal called gonadotropin-releasing hormone. The pituitary gland responds to this signal by releasing hormones called gonadotropins, which stimulate the growth of the sex glands (the testes in boys and the ovaries in girls). The growing sex glands secrete the sex hormones testosterone in boys and estrogen in girls. These hormones cause the development of secondary sex characteristics, including facial hair and muscle mass in boys, breasts in girls, and pubic and underarm hair and sexual desire (libido) in both sexes.

Some adolescents do not start their sexual development at the usual age.

In boys, delayed puberty is more common and is defined as

  • No enlargement of the testes (testicles) by age 13 or 14

  • A time lapse of more than 4 years from the start of growth of the genitals to the completion of growth of the genitals

In girls, delayed puberty is defined as

  • No breast development by age 12 or 13

  • A time lapse of more than 3 years from the start of breast growth to the first menstrual period

  • No menstruation (amenorrhea) by age 15

For girls, timing of puberty is also affected by race and ethnicity. Puberty begins earlier in Black and Hispanic girls compared to White girls (see Early Puberty).

Milestones in Sexual Development for Girls and Boys

During puberty, sexual development occurs in a set sequence. However, when the changes begin and how quickly they occur vary from person to person.

For girls, puberty begins around age 8 to 13 years and lasts about 4 years.

For boys, puberty begins around age 9 to 14 years and lasts about 4 to 6 years.

The chart shows a typical sequence and normal range of development for the milestones of sexual development.

Causes of Delayed Puberty

In the majority of cases, delayed puberty represents a normal variation, which may run in the family (also called constitutional delay of puberty). These adolescents have a normal growth rate and are otherwise healthy. Although the growth spurt and puberty are delayed, they eventually proceed normally.

Various disorders, such as poorly controlled diabetes mellitus, inflammatory bowel disease, kidney disease, cystic fibrosis, and anemia, can delay or prevent sexual development. Development may be delayed or absent in adolescents receiving radiation therapy or cancer chemotherapy. Puberty may also be delayed by autoimmune disorders (such as Hashimoto thyroiditis, Addison disease, and some disorders that directly affect the ovaries). A tumor that damages the pituitary gland or the hypothalamus can lower the levels of gonadotropins or stop production of the hormones altogether.

In boys, delayed puberty may be caused by decreased production of testosterone, sperm, or both (hypogonadism).

Adolescents who become very thin because of undernutrition or an eating disorder often have delayed puberty. Excessive exercise may cause delayed puberty, especially in girls, who may have no menstrual periods (amenorrhea).

Chromosome abnormalities, such as Turner syndrome in girls and Klinefelter syndrome in boys, and other genetic disorders can affect the production of sex hormones. One of these genetic disorders, Kallmann syndrome, affects only gonadotropin production without affecting production of other hormones.

Constitutional delay of puberty

Some children are normal but simply do not start puberty at the usual age, a phenomenon called constitutional delay of puberty. Constitutional delay is more common among boys, and many children have a family history of delayed puberty in a parent or sibling.

Short stature is common during childhood and adolescence in children with constitutional delay, but at the expected time of puberty, growth often declines because the growth spurt that typically occurs at puberty is delayed. As a result, there is a noticeable difference in height between affected children and their peers during the early adolescent years. These children typically show signs of puberty by age 18 and ultimately reach a normal height and develop normally. However, the delay may cause anxiety.

Constitutional delay is not caused by hormonal or genetic problems or an underlying disorder (such as inflammatory bowel disease or eating disorders), but doctors may evaluate children to rule out other causes of short stature and delayed puberty.

Symptoms of Delayed Puberty

In girls, breast development, pubic hair growth, the first menstrual period, or a combination do not occur.

In boys, genital growth, pubic hair growth, or both do not occur.

Short stature, poor speed of growth, or both may indicate delayed puberty in either sex.

Adolescents who have delayed puberty may be noticeably shorter than their peers, which may result in teasing or bullying, and they often need help coping with and managing social concerns. Boys are more likely than girls to feel psychological stress and embarrassment because of short stature and delayed puberty, but school and social performance may be affected in both boys and girls.

Diagnosis of Delayed Puberty

  • A physical examination

  • Bone age x-ray

  • Blood tests

  • Sometimes magnetic resonance imaging

  • Genetic testing

  • Pelvic ultrasonography (for girls)

The initial evaluation of delayed puberty should consist of a complete history and physical examination to evaluate pubertal development, nutritional status, and growth. Doctors also ask whether children have a family history of delayed puberty.

Doctors often take an x-ray of the child's left hand to see the level of bone maturity (called a bone age x-ray). A bone age x-ray may show that a child’s bones have a less mature appearance than they should for a typical child of that age.

Magnetic resonance imaging (MRI) may be done to make sure that there is no brain tumor or structural abnormality in the pituitary gland.

Doctors take blood samples and do basic laboratory tests to look for signs of chronic disease and to determine hormone levels. Blood samples may be used for genetic testing in some children.

Doctors usually evaluate boys who have no signs of puberty by age 13 or 14 years. They usually evaluate girls who have no signs of puberty by age 12 or 13 years or who have not menstruated by age 15 years. If these adolescents otherwise appear healthy, they most likely have constitutional delay. The doctor may decide to re-examine these adolescents at 6-month intervals to make sure that puberty begins and progresses normally.

Girls with severely delayed puberty should be evaluated for primary amenorrhea. This evaluation includes an ultrasound of the pelvis and other blood and genetic tests.

Treatment of Delayed Puberty

  • Treatment of cause

  • Hormone therapy

Treatment of delayed puberty depends on the cause. When an underlying disorder is the cause of delayed puberty, puberty usually proceeds once the disorder has been treated.

An adolescent who is naturally late in developing needs no treatment, but if the adolescent is severely stressed by delayed or absent development, some doctors may give supplemental sex hormones to begin the process sooner. This treatment is much more common among boys. Children with delayed puberty often need additional support from parents, family members, and friends to ensure they have a healthy body image and self-esteem.

If boystestosterone starts puberty, causes the development of some masculine characteristics (virilization), and does not prevent adolescents from reaching their adult height potential.

In girls, low doses of estrogen may be started with pills or skin patches. This estrogen therapy may be used to induce puberty or, in some cases, such as in girls who have Turner syndrome, may be needed for long-term hormone replacement.

Genetic disorders cannot be cured, but hormone therapy may help sex characteristics develop.

Surgery may be needed to remove pituitary tumors, and these children are then at risk of hypopituitarism (a deficiency of one or more pituitary hormones).

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