This article presents the preliminary findings of the Survey on Teenag
ers and Youth Reproductive Behavior in the Metropolitan Area of Mexico
City, which contains information on 1010 teenagers and young adults f
rom 10 to 25 years of age interviewed in 1987. The average age was 17
years, 51.7 per cent of those interviewed were male and 48.3 per cent
were female. A total of 14.6 per cent were married, being the average
age at marriage 19.2 years for males and 17.8 years for females. Menar
che occurred at an average age of 12.4 years, and spermarche at 14. Of
those interviewed, 32.7 per cent have had sexual intercourse at least
once in their lives. The average age at which sexual activity had beg
un, in the case of males, was 16 years and for females, 17 years. Of t
his group, 33.8 per cent stated that they had used some form of contra
ception during the first sexual intercourse; the contraceptive methods
used most often were rhythm and withdrawal. The main source of supply
of other methods is the pharmacy, in 67 per cent. 18.4 per cent of wo
men had been pregnant, and 20.4 per cent of men's partners had present
ed this same condition. The first pregnancy occured at 17.8 years for
women and 18.7 for men. Of those men and women with a pregnancy experi
ence 66.1 per cent and 57.3 per cent, respectively, stated that their
first pregnancy was an unplanned one. Also, first pregnancy was relate
d to their first marriage in 48.1 per cent of women and 82.4 per cent
of male. The data presented here will reinforce current knowledge and
will enable us to obtain a profile of the reproductive behavior of tee
nagers and young adults in the metropolitan area of Mexico City.