title: Does pregnancy protect against ovarian cancer?
abstract: A clear inverse relation between average completed family size and mortality from ovarian cancer in different populations of women is seen from one country to another; for successive generations of women living within the same country; in married and single women; and in different social, religious, immigrant, and ethnic groups. The findings suggest that pregnancy--or some component of the child-bearing process--protects directly against ovarian cancer. This protection seems to persist throughout life. The more-than-twofold increase in the age-standardised ovarian-cancer death-rate in England and Wales since 1931 can be explained largely by changes in the average completed family size.
mesh_terms: D000328:Adult; D002170:Canada; D004739:England; D005060:Europe; D005191:Family Characteristics; D005260:Female; D049672:History, 19th Century; D049673:History, 20th Century; D006801:Humans; D007564:Japan; D008875:Middle Aged; D010051:Ovarian Neoplasms / Q000453:epidemiology* / Q000209:etiology / Q000266:history / Q000401:mortality; D010298:Parity; D011247:Pregnancy; D012923:Social Class; D014481:United States; D014852:Wales