There is also substantial variation in measurement in between persons. Long term breast expansion through puberty is because of estrogens together with The expansion hormone. Feminine humans are the sole mammals that forever build breasts at puberty; all other mammals build their mammary tissue throughout the latter duration of pregnancy. https://grok.com/share/c2hhcmQtMw%3D%3D_5ad6450c-533d-442c-a09c-9f7bce1babfb