Giving birth confers on women some protection against ovarian cancer. A new study suggests that the later in life the last pregnancy happens, the better the protection.
Malcolm C. Pike of the University of Southern California in Los Angeles and his colleagues assessed 477 women who had ovarian cancer and 660 women without it. Women who had four or more full-term births were only one-third as likely to get ovarian cancer as were women who had never had a child, bolstering earlier findings (SN: 7/5/97, p. 7). Even incomplete pregnancies conferred significant protection. Some scientists hypothesize that more pregnancies correspond to fewer lifetime ovulations, less wear and tear on the ovaries, and hence a lower cancer risk.