Pubertal changes in girls

At 11 to 12 years old the rate of growth for girls is typically at its maximum at around 8½ to 9½ cm per year. At this time, a girl will be customarily be entering Tanner stage 2. The breast buds and pubic hair starting to develop. Towards the end of stage 2, the growth rate slows, the ovaries begin to produce mature ova and the first menstrual cycle usually commences. This is known as menarche. The timing of menarche is commonly around 2 years after the initial pubertal changes start to be seen.

During Tanner stages 3 and 4 there is an increase in the size of the breasts and amount of pubic hair. A mound of areolar and nipple that projects from the breast develops. There is a broadening of the pelvis and a redistribution of body fat, typically around breast and hips.

By 16 years old, most girls will have reached stage 5 and their growth is slowing and stopping. The secondary sexual characteristics are fully formed, only the nipple projects from the breast and a regular monthly cycle is typically well developed.