Impact of Estrogens
Estrogens have a significant impact on a female's body shape. They are produced in both men and women, but their levels are significantly higher in women, especially in those of reproductive age. Besides other functions, estrogens promote the development of female secondary sexual characteristics, such as breasts and hips. As a result of estrogens, during puberty, girls develop breasts and their hips widen. However, the presence of testosterone in a pubescent female inhibits breast development and promotes muscle development; while estrogens act in the other direction.
Estrogen levels also rise significantly during pregnancy. A number of other changes typically occur during pregnancy, including enlargement and increased firmness of the breasts, mainly due to hypertrophy of the mammary gland in response to the hormone prolactin. The size of the nipples may increase noticeably. These changes may continue during breastfeeding. Breasts generally revert to approximately their previous size after pregnancy, although there may be some increased sagging.
Breasts can decrease in size at menopause if estrogen levels decline.
Read more about this topic: Female Body Shape
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