Three major factors accounting for significant shape and size changes within the breast need to be considered within each patient. A patient may have one or all three of the components acting to produce undesirable changes in the breasts. The factors are:
Weight fluctuations, such as large weight-gain followed by a significant loss, stretching out the skin envelope, and then removing the contents (fat).
Multiple pregnancies acting to increase the volume of breast tissue that pushes on the overlying skin envelope, and atrophies between periods of pregnancy.
Loss of elasticity in the connective tissue scaffolding that keeps the skin from stretching too far. This may be related to aging, genetics, or both.