Early Childhood (1-10 years old)

The breast development process is stagnant during early childhood. The number of milk ducts and lobules formed
earlier during the embryonic period is maintained.

Puberty

Driven by the surge of estrogen hormones, the breast tissues develop and enlarge markedly, thus the breasts grow bigger into
a rounded shape. The growth in breast size is dependent on nutritional consumption, physical activity and of course the
estrogen levels (female hormones).

Pregnancy

Pregnancy brings about the fullness of breast growth and development. The rise in estrogen levels significantly increases
the size of the lobules, promotes the dilation of lactiferous ducts to form lactiferous sinus and stimulates the enlargement and
protrusion of the nipples. But after breastfeeding, the breasts shrink back to their normal size. This proves that the increase in
estrogen levels can induce catch-up growth of the breasts.