At what age is a boy considered to have delayed puberty? What can be done?

Author: Bai Wenjun, Chief Physician, Peking University People's Hospital

Vice Chairman of the Sex Medicine Committee of the Chinese Society of Sexology

Reviewer: Zhang Yi, Chief Physician, Peking University International Hospital

After a boy is born, he will go through several stages: infancy, early childhood, preschool, school age and adolescence. Among them, the growth and development speed of infancy and adolescence is the fastest.

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1. How to determine whether a boy has begun puberty?

What people usually pay attention to is height, whether the Adam's apple has grown, whether the voice has changed, whether there is beard and pubic hair, and whether the penis has developed.

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Professional doctors mainly observe the height, development of sexual organs and sexual characteristics, such as penis length, testicle size, pubic hair density, Adam's apple and armpit hair, etc. These are some external manifestations; there are also some internal manifestations, mainly testing sex hormones to see whether gonadotropin and testosterone have increased.

To judge the development of puberty, we mainly look at two indicators. One is the development of pubic hair. No pubic hair is P1, a few hairs are P2, a tuft of hair is P3, a lot of hair is P4, and adulthood is P5. The second is the development of the genitals. G1 is no development, G2 is the development of the testicles, G3 is the development of the penis, and G4 is the development of the glans penis.

The development of boys' sexual organs and characteristics generally begins at the age of 11-12. If there are no changes in the testicles, penis, pubic hair, voice, etc. by the age of 14, it is considered to be delayed puberty.

Typical manifestations are: height is not as tall as other children of the same age; secondly, the voice is rougher than other children, but he is still relatively shrill; the penis and testicles are relatively small; in terms of personality, other children are more stable, but he still feels particularly immature.

2. What examinations are needed for boys with delayed puberty?

There are many reasons for delayed puberty in boys, mainly problems with the gonad axis. The gonad axis refers to the hypothalamus, pituitary gland, and testicles. The gonad axis starts to activate when the boy is 11 or 12 years old. If it does not activate, the boy will not develop.

There are functional abnormalities in the hypothalamus, pituitary gland, and testicles, including congenital and acquired causes, the most common of which are congenital. The most common congenital causes are chromosomal problems, gene mutations, imperfect development of the endocrine system, etc., which can lead to delayed or undeveloped development; acquired causes are mainly pituitary damage, ischemia or tumors, pituitary secretion disorders, interference with the activation and start-up of endocrine organs, leading to delayed, undeveloped or interrupted development.

When boys have delayed puberty, they usually first undergo a physical examination to check the development of their height, sexual organs, and secondary sexual characteristics.

Test sex hormones, the most important indicators are gonadotropin and testosterone, to see if they are too low.

Other tests, such as measuring bone age, can be done to see if there is any difference between bone age and actual age. Generally, if puberty is delayed, bone age will be delayed. For example, if the actual age is 14, the bone age may only be 11-12 years old.

Do an MRI to see if there are any lesions in the pituitary gland, such as ischemia, tumors, developmental abnormalities, etc.

For those who are too short, you can measure growth hormone, thyroid hormone, adrenal cortex hormone and other development-related hormones.

If the cause cannot be found, in some cases it is necessary to test for gene mutations. Gene sequencing can be done to look at the gene mutation situation.

3. How to treat delayed puberty in boys?

If boys have delayed puberty, drugs can be used to simulate puberty. Development is mainly caused by sex hormones, and in men it is mainly testosterone. Testosterone supplementation, oral or intramuscular injection, can simulate normal puberty.

If development still fails, the simulation should be continued until the end of puberty. Normal puberty development generally takes 3-5 years, and treatment should be continued according to the required amount of testosterone until the end of puberty.

After puberty is completed, see if the gonad axis can be activated. If it cannot be activated on its own, the body's own testosterone production is insufficient or cannot be produced, and it must be maintained. Some require lifelong treatment.

Previously, it was believed that treatment should be started at the age of 14, when development has not yet begun. Now, it is advocated to start treatment as early as possible. The earliest treatment can be started at the age of 12, and testosterone supplementation is relatively safe.