Adolescence is a period of transition from adolescence to adulthood, i.e., from the emergence of secondary sexual characteristics to sexual maturity and physical development. A series of morphological, functional, metabolic, psychological, intellectual, and behavioral changes occur in the body at this time, most notably the rapid development and maturation of the reproductive system.
The most obvious is the rapid development of the reproductive system. The most important sign of physical development is the sudden increase in growth when puberty is reached. The growth of males starts to accelerate around 12 years of age, and at 14-15 years of age is the stage of the fastest growth in height, reaching the peak of the height growth rate, which can be an average of about 10 cm per year, boys grow a total of 20-30 cm, after 16 years of age the growth rate slows down, generally at the age of 18-20 years of age height growth stops. The growth spurt of girls appears 2 years earlier than that of boys. 10 weeks of age or so began to accelerate growth, 11 to 12 years of age is the fastest growing stage of height, the average annual growth of about 8cm, girls a total of 15 to 25 cm taller. If there is no growth spurt during puberty, then most of the height in adulthood is not ideal. The most obvious aspect of entering puberty is the rapid maturation of the gonads. In boys, testicular enlargement begins around the age of 12, followed by penis enlargement, scrotal skin loosening and coloring, pubic hair and axillary hair, followed by beard, throat knot and voice change. Testicular enlargement is the earliest sign of puberty in boys. The first ejaculation occurs on average at the age of 14 to 15 weeks. In girls, the onset of puberty is two years earlier than in boys, with breast development starting around the age of 10, followed by the development of labia majora and labia minora, pigmentation, increased vaginal discharge, and then the appearance of pubic and axillary hair. The average age of menarche is 12.5 to 13 years. Breast development is the first secondary sexual characteristic to appear in girls, while the onset of menarche is the arrival of late adolescence and means that the rapid growth period of height has ended and has entered a period of slow growth. Generally, after menarche, the average height growth is only about 5-7 cm.
Delayed growth during puberty
Delayed puberty is diagnosed when there are no sexual signs after the age of 14 for girls and 15 for boys, or when girls still do not have their first menstrual period at the age of 18.
Causes of delayed puberty
1.Physical delay in puberty. Due to the temporary low function of hypothalamus, pituitary and gonadal axis, the development of reproductive organs and sexual characteristics is significantly delayed. After several years of delay, the hypothalamus-pituitary-gonadal axis starts to activate and puberty develops. In most cases, pubertal development begins after the actual age of 16 to 17 years old, at the latest until the age of 20 years old in boys and 18 years old in girls, and is more common in boys, accounting for about 50% of delayed puberty cases in boys. There is often a family genetic tendency.
2, systemic chronic diseases or severe malnutrition. It refers to chronic systemic diseases, such as cyanotic congenital heart disease, liver cirrhosis, uremia, diabetes, anorexia nervosa, chronic infectious diseases, and severe malnutrition. The child exhibits a significant delay in physical development, development of reproductive organs and sexual characteristics. If the primary disease is treated and alleviated or even cured, pubertal development can be initiated and the development of physical and sexual characteristics accelerated.
Turner syndrome is the most common form of female gonadal dysgenesis, which is caused by the absence or aberration of the female x chromosome. 45,x karyotypes are the most common, while other chimeric karyotypes such as 45,XO/46,XX,45,XO/46,XY,isobaric X karyotype 46,Xi( Xq), etc. The children show short stature, typically with short neck, webbed neck, facial nevus, low hairline, barrel chest, widened breast spacing, and elbow valgus. In addition to short stature, there is no development of secondary sexual characteristics during puberty, and most of them do not have menstruation.
4. congenital hypospadias (Klinefelter syndrome), which is caused by abnormal sex chromosomes in males. The basic chromosomal karyotype is 47, XXY, and others are seen with more X and/or Y chromosomes and multiple chimeric karyotypes, such as 48, XXXY, 48, XXYY, etc. The child presents with a small testicle size and hardness to touch since childhood. At puberty, they are taller than their peers, have longer lower limbs, a slender body, narrow shoulders, a wide pelvis, and 1/3 of the children have enlarged breasts. The external genitalia are male, but the testes are small, the scrotum has little pigmentation, and the pubic hair, beard, and body hair are sparse. Where the x chromosome is more than 3 cases, the low intelligence is more significant.
5. Acquired gonadal damage. Such as testicular inflammation, ovarian inflammation, trauma/surgical injury, drug damage, radiation damage, etc.
6. Congenital or acquired disorders of the hypothalamus and pituitary gland. Children with congenital hypothalamic GnRH secretion or pituitary GnRH receptor defects; or children with acquired central nervous system diseases involving the hypothalamus and pituitary gland. Commonly, ischemic-hypoxic encephalopathy, toxic encephalitis, meningitis, traumatic brain injury, and radiation exposure may cause hypogonadotropic hypogonadism in the child.
Diagnosis of delayed pubertal development
Delayed puberty is diagnosed when there are no sexual signs after the age of 14 for girls and 15 for boys, or when girls still do not have their first menstrual period at the age of 18.
Diagnosis of delayed puberty
1.Detailed medical history: birth history, birth weight, growth and development of the child, past history, family history
2. Physical examination: measurement of height, weight, physical development, development of external genitalia and secondary sexual characteristics, etc.
3. Hypothalamus and pituitary gonadal axis function measurement: sex hormone and gonadotropin measurement; GnRH excitation test; HCG excitation test; growth hormone (GH) excitation test
4.Chromosome karyotype analysis
5.Bone age
6.Ultrasound examination
7.Magnetic resonance examination, etc.
8.Other
Treatment of delayed puberty
1.Physical delay in puberty development
Generally, no treatment is needed. The following treatments can also be given to patients who are 16 years old or older in males and 15 years old or older in females.
(1) Oral oxandrolone or fluoxymesterone for 6 to 12 months in males can induce puberty initiation and masculinization. Testosterone undecanoate (Anxiong) can also be given orally, or testosterone undecanoate can be injected intramuscularly for six months and discontinued for 3 to 6 months for observation, and puberty initiation can be started in some children.
(2) Females first take oral ethinyl estradiol.
After 3 months, progesterone is added to induce menstruation by an artificial cycle. If spontaneous sexual development does not occur, the treatment can be repeated for 2-3 courses, and most of the children can have puberty.
2.Delayed puberty due to systemic chronic diseases and severe malnutrition
If the primary disease is actively and effectively treated, puberty can be initiated if the disease can be reduced or even cured. However, many of these children cannot be completely cured of their primary serious systemic chronic diseases, so even if the above treatment is given, the results will not be very good, and their physical development, reproductive organs and sexual characteristics will still be poor in adulthood.
3. Congenital ovarian insufficiency (Turner syndrome)
The typical child with Turner syndrome has short stature and underdeveloped gonads. The clinical supervisor uses estrogen replacement therapy to induce the development of secondary sex characteristics, after which an artificial cycle can be established. Three to six months after the start of treatment, the genitalia and breasts develop, subcutaneous fat is deposited, and the body becomes progressively more feminine, and treatment with recombinant human growth hormone is combined to improve their height.
4.Klinefelter syndrome
Typically, children with Klinefelter syndrome cannot produce sperm in the testes and therefore cannot have children. The use of androgen replacement therapy can only induce the development of sexual characteristics. The method can be used for the treatment of somatic puberty delay as described above.
5.Acquired gonadal injury
Children with acquired testicular injury can be treated with human chorionic gonadotropin (HCG) to improve the spermatogenic function and testosterone secretion of the testes if they still have some degree of spermatogenic function and testosterone secretion function. In addition, the above treatment plan for somatic puberty delay can also be used.
6. Delayed puberty due to congenital and acquired hypothalamic-pituitary lesions
(1) Congenital, hypothalamic pituitary lesions caused by delayed puberty
GnRH can be administered subcutaneously in a pulsatile manner through a micropump simulating the pattern of pulsatile secretion of hypothalamic GnRH, which may lead to improvement in the function of gonadotropin secretion by the pituitary gland after a period of treatment. In male children, HCG injections may be given intramuscularly to help promote improved testicular function. HCG injections should not be used in female children to avoid rupture of follicular cysts.
(2) Delayed puberty due to acquired hypothalamic-pituitary disorders
Once diagnosed, tumors in the hypothalamic-pituitary region should be treated promptly using stereotactic surgical techniques. In children with severe damage to the hypothalamus and pituitary gland due to various acquired causes, HCG injection and sex hormone replacement therapy can improve the development of reproductive organs and sexual characteristics to a certain extent, but they are often infertile.
Parents should pay attention to their children’s gonadal development. If girls are 14 years old and boys are 15 years old without the appearance of sexual characteristics, or if girls still do not have the first menstruation at the age of 18, they are considered to have delayed pubertal development and should be promptly seen at the pediatric endocrine clinic.