Breast size has long been surrounded by myths, but biology provides a much simpler explanation. A woman’s breast size is primarily influenced by genetics, hormones, and body composition—not by anything related to the vagina. Genetics play the biggest role. If fuller breasts are common among women in a family, future generations are more likely to share that trait, although individual results can vary. Hormones also have a major impact during puberty, pregnancy, and breastfeeding, when estrogen and progesterone stimulate breast development and increase glandular and fatty tissue. Some hormonal medications may also cause temporary changes in size. Body fat is...
Continues…