Some women are just lucky not to get them. Stretch marks are from changes in the elastic supportive tissue under the skin. AnswerParty!
Stretch marks or striae (singular stria), as they are called in dermatology, are a form of scarring on the skin with an off-color hue. They are caused by tearing of the dermis, which over time may diminish, but will not disappear completely.
Stretch marks are often the result of the rapid stretching of the skin associated with rapid growth or rapid weight changes. Stretch marks may also be influenced by hormonal changes associated with puberty, pregnancy, bodybuilding, hormone replacement therapy, etc. Medical terminology for these kinds of markings includes striae atrophicae, vergetures, stria distensae, striae cutis distensae, lineae atrophicae, linea albicante, or simply striae. Stretch marks formed during pregnancy, usually during the last trimester, and usually on the belly, but also commonly occurring on the breasts, thighs, hips, lower back and buttocks, are known as striae gravidarum. Obstetrics
The reproductive system or genital system is a system of sex organs within an organism which work together for the purpose of reproduction. Many non-living substances such as fluids, hormones, and pheromones are also important accessories to the reproductive system.[dead link] Unlike most organ systems, the sexes of differentiated species often have significant differences. These differences allow for a combination of genetic material between two individuals, which allows for the possibility of greater genetic fitness of the offspring.
Brassiere measurement (also called brassiere size, bra size or bust size) refers to determining what size of bra a woman wears and mass-producing bras that will fit most women. Bra sizes usually consist of a number, indicating a band size around the woman's torso, and one or more letters indicating the breast cup size. Bra cup sizes were invented in 1932 and band sizes became popular in the 1940s.
Bra sizes vary from one manufacturer to another, and from country to country. Women's bodies and breasts may not conform to the sizes offered by companies. As a result, some women have a difficult time finding a properly fitted bra. Up to 80% of women wear the wrong size bra causing 40% to 60% to experience pain of one kind or another.]citation needed[
Striae gravidarum or pregnancy stretch marks, is a form of scarring of the skin of the abdominal due to sudden weight gain during pregnancy. These off-color blemishes are symptoms of pregnancy caused by the tearing of the dermis, resulting in atrophy and loss of rete ridges. These scars often appear as reddish or bluish streaks on the abdomen, and can also appear on the breasts and thighs. Some striae disappear with time, while others remain as permanent discolorations of the body.