A frequently quoted statistic in sex research is the number of people in a given category who have engaged in "premarital sex." As a statistic in sex surveys, premarital sex is defined as penile-vaginal intercourse that takes place between partners before they are married. However, the term premarital sex is misleading for two reasons. First, as a measure that is frequently used to indicate the changing sexual or moral values of American youth, it excludes a broad array of noncoital heterosexual and homosexual activities. For some people, abstaining from coitus before marriage might not reflect a lack of sexual activity. Second, the term premarital has connotations that may seem highly inappropriate to some people:

I really hate those survey questions that ask, "Have you engaged in premarital sex?" What about those of us who plan to remain single? Does this mean we will be engaging in "premarital sex" all of our lives? I object to the connotation that marriage is the ultimate state that all are supposed to evolve into. (Authors’ files)

Because of these limitations, we avoid using the term premarital sex in subsequent discussions. We now turn to some of the available data on sexual intercourse during adolescence; then we look at two related areas—adolescent pregnancy and the use of contraceptives.