Early puberty in girls
Puberty occurs when physical changes transform a child into an adult capable of producing a baby. Some girls go through puberty at a young age: this is called precocious puberty.
What happens during puberty?
The pituitary gland at the base of the brain is responsible for producing gonadotrophins: these are luteinising hormone and follicle-stimulating hormone.
At birth, their levels are high, but they decrease within a few months and remain low until the onset of puberty. When the levels of these two hormones increase at the start of puberty, they trigger the production of the sex hormones in the ovaries in girls. One of them is oestrogen, which is primarily responsible for stimulating physical changes in the breasts, ovaries, uterus (womb) and vagina so they reach maturity.
What are the signs of puberty in girls?
Breast budding is often the first sign of puberty and usually starts at about age 11, but anywhere between eight and 14 years is normal. However, some girls may first notice an increase in hair on their arms and legs. Hair appearing in the armpits and pubic area also happens early on.
Another early sign of puberty is a large growth spurt, with girls gaining about 17-18% of their adult height. Most girls will gain weight and notice more body fat along their upper arms and back and around their thighs. Their hips will also grow rounder and wider while their waist becomes narrow.
About two years after breast buds appear, the menstrual cycle (periods) will start.
What is considered early, or precocious, puberty in girls?
Puberty usually takes four to five years and typically occurs between 10 and 14 years in girls, but some girls will go through puberty earlier or later without any reason for concern. The lower end of the normal range in the UK is considered to be eight years, but this can vary according to ethnic background. If there are signs of puberty before eight years in girls, it is considered to be early, or precocious, puberty.
Occasionally, only one area of the maturing process of puberty begins on its own.
When only breast development is involved it is known as premature thelarche. If there is only body hair or pubic hair development, it is known as premature adrenarche or pubarche.
These conditions occur more often than true central early puberty, and there is a difference between how they are managed.
What problems are associated with early puberty in girls?
Because the children will have accelerated growth spurt early on, they will stop growing early on and may be short as adults, or they may have weak bones.
Girls who go through puberty early will need to deal with having their menstrual cycles at an earlier age than their friends. However, their brain will also be more mature, so this may not be as problematic as it might seem.
Early puberty has been associated with behavioural and emotional difficulties such as social integration and the ability to concentrate at school. One study by researchers from the University of Bristol and the University of Cambridge found a link between the timing of girls' first periods and depressive symptoms among teenagers.