M2 (budding stage): The breast and the nipple are slightly elevated, and some glandular tissue is felt on palpation. The areola is enlarged.
M3: The breast and the areola are further enlarged, and their contour forms a smooth curve when inspected from the side.
M4: The areola forms an elevated mound projecting from the surrounding breast.
M5 (mature breast): Only the nipple is elevated, and the areola is aligned with the contour of the breast.
Pubic hair
P1 (as in a child): The pubic hair does not differ from the hair of the abdomen.
P2: Some long, slightly pigmented, downy, straight or slightly curled hair on the labia or at the base of the penis.
P3: Notably darker, stronger, and curlier hair spreading slightly to the symphysis.
P4: Adult-type hair but on a clearly smaller area. Does not extend to the inner aspect of the thighs.
P5: Adult-type hair with horizontal upper border that does not spread towards the navel but does spread to the inner aspect of the thighs.
Male genitals
G1: The testes, the scrotum, and the penis are of about the same size and proportions as in early childhood.
G2: The scrotum and the testes are enlarged, the skin over the scrotum is slightly erythematous and thinner, but the penis is not yet enlarged.
G3: The penis has grown longer, and the scrotum and the testes are further enlarged.
G4: The penis has grown further, also in diameter, the glans has developed, and the testes and the scrotum are further enlarged, the colour of the scrotum has become darker.
G5: The genitals are the same size and shape as in adults.
Screening rules for pubertal development
Screening rules for pubertal development
Not before
At the latest
* Length of the testes 25 mm or more
Girls
M2
8 yrs
13 yrs
P2
8 yrs
13 yrs
Accelerated growth
9 yrs
13 yrs
Menarche
10.5 yrs
15.5 yrs
Boys
G2*
9 yrs
13.5 yrs
P2
9 yrs
13.5 yrs
Accelerated growth
10 yrs
15 yrs
A parental deviation of at least 1 year in pubertal development from the average in the population (menarche at 13 years, fastest growth in the father at 13-14 years) allows the child a further deviation of one year in the same direction; however, it is important to inform the adolescent about this.
Adoption increases the risk of precocious puberty. However, the same screening rules are applied to adopted children.
Normal growth at puberty
Pubertal growth has three stages.
Slow growth in early puberty
A growth spurt lasting about two years
Final slowing and cessation of growth
The fastest spurt occurs in girls at the average age of 11-12 years, and in boys at the average age of 13-14 years.
The fastest growth in girls usually occurs at stage M3. In about one girl in four the growth spurt occurs before the pubic hair develops, but always before menarche. After menarche the height increases by 3-11 cm, on average 7 cm.
If a boy has no pubic hair, the growth spurt is yet to come. It usually occurs at stage G4. If the penis has not yet increased in circumference and the glans has not developed, the remaining growth in height is 12-30 cm.
Precocious puberty
Examination in primary health care
In primary care the history should be taken and a physical examination performed to determine whether the condition is abnormal and whether indications for referral exist. Further assessment should be performed at a specialized unit. The investigations should be started without delay.
Determine the pubertal history of close family members.
Take the medical and other personal life history.
Was the patient born small for gestational age (SGA)?
Did the patient suffer central nervous injury or undergo central nervous treatment?
Ask about vaginal bleeding.
Ask about use of sex hormones or natural products in the family (particularly oyster mushroom capsules, tea tree and lavender oils).
Is the child adopted?
Growth of a breast or breasts (telarche) in a girl under 2 years of age without accelerated growth and signs of puberty can be monitored in primary health care. Specialized care should, however, be consulted at a low threshold.
Assess whether growth has been normal, whether growth velocity has constantly increased (suggesting a congenital abnormality) or changed.
Perform thorough examination of pubertal status.
Identify symptoms of increased intracranial pressure.
Examination in specialized care
Specialized hormone tests (e.g. GnRH test, inhibin B, sex hormone levels), x-ray for bone age determination and more extensive imaging studies (e.g. ultrasonography of the ovaries and the uterus, central nervous system imaging)
True precocious puberty is more common in girls than in boys. The cause of pubertal precocity should always be sought for.
Isolated vaginal bleeding: colposcopy should be performed in specialized care to rule out a foreign body or botryoid sarcoma.
Adrenarche
Adrenarche means beginning of the secretion of male sex hormones by the adrenal glands. Clinical signs of adrenarche include growth of underarm and pubic hair, adult-type underarm sweating, hair becoming greasy, comedos and acne.
In precocious adrenarche, the above clinical findings occur in girls before the age of 8 and in boys before the age of 9 years. No further examinations are needed if at puberty screening nothing abnormal is found except for the P stage and/or growth is normal according to screening rules.
If at puberty screening the findings for the M or G stage also differ from normal and/or growth has accelerated, examinations should be performed in specialized health care, because adrenarche as such will not cause growth of the breasts or testes; these are signs of onset of central puberty.
Adrenarche and central puberty may occur simultaneously.
Gynaecomasty of puberty in boys
Gynaecomasty is associated with normal puberty and it is usually a transient phenomenon of unknown aetiology that occurs in most boys at the stage of fastest growth in height and of the genitals.
It is associated with tenderness of the breast that may disturb sports activities. The areola is normally not pigmented, and glandular tissue can be detected on palpation (diameter < 3 cm).
The glandular tissue often disappears in a few months but the larger the breast is, the slower the rate of regression.
If gynaecomasty of puberty in a boy persists for more than 2 years, spontaneous resolution is unlikely and a surgical operation in a plastic surgery unit may be considered.
Delayed puberty
Although most cases fall within the wide limits of normal variance (2.5% of adolescents develop 2 years later than their peers), counselling and support for the adolescent are always indicated. Acceleration of development with sex hormone treatment is often indicated.
Hypogonadic adolescents should be identified early (see below), and sex hormone substitution should be started before they differ clearly from their peers.
Primary investigations
Can partly be performed in primary care but a specialist should be consulted if necessary.
Determine the growth and maturation history of close family members (a slowly maturing patient often has close relatives with similarly delayed pubertal development). Are there chronic illnesses, such as coeliac disease or inflammatory bowel disease, in the close family?
Does hypogonadism, impaired sense of smell, cheilopalatoschisis or childlessness occur in the family?
Does the adolescent have a history of cryptorchism, orchitis, testis surgery, hypospadia or central nervous injury? Has the patient received corticosteroids, radiotherapy, cytotoxic drugs or hormone treatment?
Are there any signs of chronic disease (e.g. hypothyroidism, coeliac disease, inflammatory bowel disease)? Is the sense of smell normal?
Analysis of growth, body proportions (sitting height)
Pubertal status, measurement of the testes; fundoscopy and visual fields, as necessary
Investigations that can be performed in primary care to clarify the situation include e.g. complete blood count, ESR, thyroid function tests, creatinine, and coeliac disease antibody tests.
Further investigations in specialized care
Always indicated if primary investigations suggest other than normal delayed maturation. Further investigations are conducted to find out whether the patient has functional pubertal delay due to e.g. a chronic disease, constitutional pubertal delay (diagnosis by exclusion; the most common explanation), or primary or secondary hypogonadism.
Investigations in specialized care include, among others, x-ray for determination of bone age, faecal calprotectin, serum inhibin B, testosterone/estradiol, LH and FSH, gonadotropin-releasing hormone (GnRH) stimulation test, and brain MRI if secondary hypogonadism is suspected.
In girls the most common cause of hypogonadism is Turner's syndrome, which should be identified no later than in childhood on the basis of consistently abnormal (slowed) growth. In Finland, about 10-12 girls with Turner's syndrome are estimated to be born annually.
The most common cause of primary hypogonadism in boys is Klinefelter's syndrome which, however, does not typically cause pubertal delay Male Hypogonadism and Hormone Replacement. Still, the condition should be recognized due to apparent underdiagnosis. The syndrome is suggested by increased height, particularly increased limb length, even before puberty (limb length disproportionate to sitting height). The testes initially increase in size (up to 30 mm) but then become smaller over a few years. In Finland, about 50 boys with Klinefelter's syndrome are estimated to be born annually.