[Reproductive health survey in young adults: sexual experience and use of contraceptives in Santiago, Chile].

A self weighted, 2 stage probability sample of households in greater Santiago was obtained to select women and men between 15 and 24 years of age in order to obtain information about knowledge of sexual aspects, sexual activity and use of contraception. 35% of females and 65% of males declared to have had premarital sexual intercourse. Mean age at first premarital coitus was 18 and 16 years for women and men, respectively. Partners were 3.5 years older for females and 2.5 years older for males. A steady boy friend was the most common first sexual partner for females. Only 20% of women and 19% of males used contraception at first coitus. Rhythm, pills and withdrawal were the most commonly used methods. Less than 4 coituses in the 2 months preceding the survey were declared by 75% of subjects. All women declared themselves monogamous; 8% of males acknowledged more than one sexual partner in the last month.