Breasts, nipples and areolas are present at birth, meaning that newborn babies already have the structure but the breast tissue is very small. It sometimes happens that newborns produce some secretion from the nipples, known as “witches milk”, but that should not be confused with breast development, which comes much later on.
In girls, breast development starts after they reach a certain age, along with the development of other secondary sexual characteristics, such as pubic hair. Breast development, however, is the first sign of maturing that is visible to others. This usually occurs a year or two before menarche, which is the first menstrual period.
The first stage of breast development starts when the ovaries starts producing estrogen. In this stage, some enlargement takes place around the areolas. The glandular tissue at this stage is called “bud”. All the components of breasts are present, but they are not yet developed and they are quite small. This stage begins with the onset of puberty and in girls in continues to develop further while in males the breasts remain as they were in this stage.
In Stage Two, the “bud” starts developing further and the tissue continues to grow. At this stage, the nipples are enlarged, which often causes embarrassment and frustration in young girls. They also become more sensitive, while the areolas become slightly darker.
This stage may be difficult to define and experts often use different criteria to decide whether a girl is in the stage two, three or four. However, it can be said that in Stage Three the breast tissue, the areolas and nipples continue growing and it usually covers the period around the first menstrual period.
In Stage Four, there is a secondary swelling under the nipples, as if there were a second budding going on in front of the previous one. It occurs in early teens or in early to late twenties.
Stage Five is the final stage of breast development. The breasts reach their final shape and size. Other changes may take place during a woman’s life, and they will affect the shape and size of breasts, but they will be caused by pregnancy, breastfeeding, obesity or aging, as well as by menopause, so they are not considered actual stages in breast development.