Sexual and reproductive healthcare for adolescents has faced some obstacles and challenges. The young population has a significant burden of disease related to unplanned pregnancy and births, as well as, sexually transmitted infections (STIs), including human immunodeficiency virus/human immunodeficiency syndrome (HIV/AIDS), maternal death and abortion. Some factors, such as lack of information about their health, difficult access to contraceptive methods, low schooling and income, violence and sexual abuse, gender inequalities, among others contribute to the persistence and increase of these problems among adolescents. The objective of the study was to analyze indicators of sexual and reproductive health of adolescents based on data from the National School Health Survey (PeNSE) in 2015, comparing them to those of 2009 and 2012.

Cross-sectional study, which has analyzed data from 9th graders - PeNSE 2015, 2012 and 2009. Prevalence was estimated with the respective 95% confidence intervals (95% CI) for indicators of sexual initiation, condom use at the last sexual intercourse, have received counseling regarding pregnancy prevention, sexually transmitted infections (STIs) prevention and free condoms availability in all three editions of the survey. Prevalence of all 2015 indicators were also estimated stratifying them by sex, administrative dependence of the school and region. Pearson's Chi² test was used to evaluate statistical differences. The complex sample was used to obtain population estimates using the Stata Survey module, version 14.0.

Prevalence of sexual initiation decreased from 30.5% in 2009 to 27.5% in 2015, as well as for condom use, from 75.9% to 66.2% in the same period. There was a decrease in the orientation of prevention of pregnancy in public schools, from 81.1% to 79.3% and of free condom in private schools, from 65.4% to 57.3%. There was a higher prevalence of use of methods other than condoms and a threefold higher prevalence of previous pregnancy among public school students (9.4 vs. 3.5%, P=0.002). About 30% of the adolescents reported combined use of condoms and another method, setting up double protection, and 19.5% did not use any method. All indicators of sexual and reproductive health analyzed in 2015 had differences according to sex (P<0.0001). It was observed that boys presented higher prevalence of sexual initiation, number of partners and less condom use, as well as received less guidance on prevention of these events than girls. North, Northeast and Central-West regions presented the worse indicators performance.

There was a decrease in sexual initiation and condom use among adolescents, greater vulnerability to STIs among boys, and pregnancy among adolescents in public schools. We also noticed a worse performance of the indicators in the North, Northeast and Central West regions, reinforcing the need to invest in sexual and reproductive education, considering the peculiarities of this population, with more attractive and empathic strategies. It is worth noting that the school is an essential locus for the transfer of contents about sexual initiation, condom use, STI prevention, among others. Thus, there are no spaces for setbacks, nor the restriction of these themes for religious reasons, or gender bias.