Adolescence is characterized by significant biological and psychological changes. During this time, the increased production of androgens leads to increased sexual behavior, and this may contribute to early initiation of sexual activity. The objectives of the present cross-sectional study of adolescents enrolled in state schools in the city of Ribeirão Preto, state of São Paulo, Brazil, were to determine the average age at the first sexual intercourse (sexarche), the average number of sexual partners, and the frequency of contraceptive and condom use. Information on the age at sexarche, number of sexual partners, use of different contraceptive methods, and use of condoms were obtained using a semistructured questionnaire. Quantitative variables are expressed as means and standard deviations (SDs), and qualitative variables as absolute and relative frequencies. The chi-squared test was used for comparisons of qualitative variables, and the Student t-test for comparisons of continuous variables. All statistical analyses were performed using SAS (version 9.4, North Carolina State University, USA). We evaluated 202 students who answered the questionnaire, 69 males (36.36%) and 133 females (63.64%). The age at sexarche for men ranged from 7 to 18 years old, and for women from 7 to 17 years old. Forty-eight girls (36.01%) and 21 boys (30.43%) were in the first year of high school, 66.94% of adolescents reported sexual intercourse, and 56.25% used a condom during the first sexual intercourse. A total of 36.72% of students said they had safe sex most of the time, and 83.59% said that the first sexual intercourse happened because they “had a crush on” the other person.

Introduction: Adolescence is characterized by significant biological and psychic changes. At this stage, increased production of androgens results in the activation of sexual behavior which may contribute to early sexual initiation. Objectives: The objectives of this study were to verify the average age of the first sexual intercourse of adolescents enrolled in state schools in the city of Ribeirão Preto / SP, and to verify the average number of students' partners and the frequency of contraceptive use and condom use in this school. population. Methods: This is a cross-sectional study to which high school adolescents were included. Information on the age of first sexual intercourse, the number of partners of the students, use of contraceptive methods and use of condoms were obtained through a semi-structured questionnaire. Quantitative variables were expressed as mean and standard deviation and qualitative variables were expressed in absolute and relative frequencies. The chi-square test for qualitative variables and the t-student test for continuous variables were used to compare the means of age and age of the first sexual relation according to the gender of the students. All statistical analyzes were developed with the help of the SAS program, version 9.4. Results: We evaluated 202 students who answered the questionnaire, being 69 (36.36%) men and 133 (63.64%) women. The sex age for men ranged from 7 to 18 years and for women aged 7 to 17 years, with 48 (36.01%) of the girls and 21 (30.43%) of the boys attended the first year of high school, 66,94% of adolescents reported sexual intercourse with 56.25% used a condom at the first sexual intercourse, but 36.72% said they had safe sex most part of the time and 83.59% confirmed that they had their first sexual intercourse happened because they "have a crush on". Conclusion: More than half of public school students had early sexual initiation, in which most did not use condom or effective contraceptive method; would like to receive information on the subject through parents and teachers and the main motivations for sexual initiation were personal choice and curiosity.

No abstract