This book presents national estimates from the National Center for Health Statistics on sexual behaviour, sexual attraction, and sexual identity in the United States; prevalence and timing of oral sex with opposite-sex partners among females and males aged 15-24 years; contraceptive methods women have used in the United States from 1982-2010; current contraceptive use in the United States (2006-2010); and use of emergency contraception among women aged 15-44. These behaviours and characteristics are relevant to birth and pregnancy rates, as well as to the incidence of sexually transmitted infections.