Precocious puberty refers to the appearance of secondary sexual characteristics before age 7 or 8 in girls and before age 9 in boys, without treatment. Paradoxically, it leads to large stature in childhood, but short stature in adulthood. Learn more about the condition, its diagnosis and the different treatment options available.
Although the average age for puberty, in other words the development of secondary sexual characteristics, is 11 for girls and 13 for boys, an increasing number of children show signs of early puberty (before age 7 or 8 in girls and before age 9 in boys).
There are two types of precocious puberty:
- Central precocious puberty (CPP, or true precocious puberty) is caused by
early maturation of the hypothalamic-pituitary-gonadal (HPG) axis by activation
of the gonadotropin-releasing hormone (GnRH) pulse. Controlled by the hypothalamus and the pituitary gland (the structures in the brain responsible for hormone secretion) that release hormones, the reproductive organs (testicles and ovaries) secrete sexual hormones (steroids) that trigger puberty.
- Peripheral precocious puberty is brought about by production of sex steroids independently of the hypothalamic-pituitary-gonadal axis. It is caused by another anomaly, such as gonadal and adrenal glands tumors, congenital adrenal hyperplasia (CAH), etc.).
Symptoms and impact on health
Precocious puberty manifests in the premature appearance of signs of pubertal development:
- in boys, these include enlarged testicles, growth of pubic hair and development of the penis;
- in girls, precocious puberty is marked by breast development, and in rare cases, the start of periods.
There are a number of negative consequences for patients:
- smaller stature in adulthood: if children grow too quickly, their growth can stop too early when they reach adulthood. Sex hormones trigger bone maturation and also stop bone formation.
- psychological distress: the early appearance of puberty can complicate relations with other children and adults (at school and in the family) and raise a lot of questions.
Central precocious puberty is usually idiopathic (there is no known cause). This is true for 80 to 95% of girls and 50% of boys where the condition occurs (a tumor is found in 50% of cases).
However, there are a number of contributing factors:
- Ethnic origin: the condition is more prevalent in girls of African or Hispanic origin than in Asian or Caucasian girls;
- Lack of exercise: is a factor that tends to accelerate the onset of puberty;
- Cultural food preferences: foods that are high in fats promote the production of the two hormones that influence sexual development, estrogen and insulin;
- Exposure to some environmental or cosmetic endocrine disruptors, (especially bisphenol A, an aromatic organic compound suspected of having a role in the onset of precocious puberty).
Worldwide, the incidence of sexual precocity is estimated at 1: 5, to 1: 10,000 children with a female/male ratio of approximately 10:1.
7 or 8
the average age of precocious puberty in girls
the average age of precocious puberty in boys.