development of the breast
Last reviewed 01/2018
The breasts develop as follows:
- stage 1: prepubertal projection of nipple
- stage 2: the breast bud
- stage 3: similar to a small adult breast
- stage 4: the areolar and nipple stand proud of the breast
- stage 5: the nipple and breast have the same contour
Breasts appear at the start of puberty from 9 to 13 years. Breast development is complete by the end of puberty, after 1.5 to 6 years.
These stages are written in notes preceded with a B, ie B1, B2 etc.
Oestrogen-17beta is the main hormone determining breast development. In addition, progesterone is involved in the promotion of alveolar development.