The study results were presented at a conference of the American Society of Plastic Surgeons.According to Rinkers research, there are several key factors. A history of cigarette smoking "breaks down a protein in the skin called elastin, which gives youthful skin its elastic appearance and supports the breast." The number of pregnancies was strongly correlated with ptosis, with the effects increasing with each pregnancy. As most women age, breasts naturally yield to gravity and tend to sag and fold over the inframammary crease, the lower attachment point to the chest wall. This is more true for larger-breasted women. The fourth reason was significant weight gain or loss (greater than 50 pounds (23 kg)). Other significant factors were higher body mass index and larger bra cup size.In Rinkers study, 55% of respondents reported an adverse change in breast shape after pregnancy. Many women mistakenly attribute the changes and their sagging breasts to breastfeeding, and as a result some are reluctant to nurse their infants. Research shows that breastfeeding is not the factor that many thought it was. Rinker concluded that "Expectant mothers should be reassured that breastfeeding does not appear to have an adverse effect upon breast appearance." Also discounted as causes affecting ptosis are weight gain during pregnancy and lack of participation in regular upper body exercise. Effect of vigorous exercise
When running, breasts may move three-dimensionally: vertically, horizontally and laterally, in an overall figure-8 motion. Unrestrained movement of large breasts may contribute to sagging over time.
Ptosis or sagging of the female breast is a natural consequence of aging. The rate at which a womans breasts drop and the degree of ptosis depends on many factors. The key factors influencing breast ptosis over a womans lifetime are cigarette smoking, her number of pregnancies, higher body mass index, larger bra cup size, and significant weight change. Post-menopausal women or people with collagen deficiencies (such as Ehlers-Danlos) may experience increased ptosis due to a loss of skin elasticity. Many women and medical professionals mistakenly believe that breastfeeding increases sagging. It is also commonly believed that the breast itself offers insufficient support and that wearing a bra prevents sagging, which has not been found to be true.Plastic surgeons categorize the degree of ptosis by evaluating the position of the nipple relative to the infra-mammary fold, the point at which the underside of the breasts attach to the chest wall. In the most advanced stage, the nipples are below the fold and point toward the ground. Signs and symptoms
A womans breasts change in size, volume, and position on her chest throughout her life. In young women with large breasts, sagging may occur early in life due to the effects of gravity. It may be primarily caused by the volume and weight of the breasts which are disproportionate to her body size. Impact of pregnancy
During pregnancy, the ovaries and the placenta produce estrogen and progesterone. These hormones stimulate the 15 to 20 lobes of the milk-secreting glands in the breasts to develop.