Abstract

This study aimed to estimate the prevalence of sexual initiation of pupils aged 10 to 14 who attended the second year of public and private high school in the IX Administrative Region of the city of Rio de Janeiro, Brazil and to identify the most vulnerable subgroups. The sample consisted of 694 pupils who were selected through cluster-based and stratified sampling by considering school type (public or private) and course type (daytime or evening). Information was collected by means of a structured self-administered questionnaire. The chi-square test (χ2) and 95% confidence intervals were used to assess the heterogeneity of proportions among subgroups. The prevalence of the event was 18.4%; it was higher in boys, in subgroups of greater social vulnerability, among those who hooked up/dated up to 14 years of age, in victims of sexual violence in affective-sexual relationships and in pupils showing health risk behaviors. The high rate of sexual initiation in early adolescence, especially in more vulnerable groups, shows that the situation must be understood and addressed by means of intersectoral public policies that take into account a social context of multiple needs rather than reproductive health alone.

Key words:
Sexual behavior; Sexual and reproductive health; Sexual violence; Adolescent

Introduction

Discoveries, social interactions and possibilities for new experiments occur during adolescence and youth in various spheres of life¹1 World Health Organization (WHO). The Sexual and Reproductive Health of Younger Adolescents: Research Issues in Developing Countries. Geneva: WHO; 2011.. Among these experiences, the first affective and sexual relationships are some of the most important ones. Sexual initiation is seen as an indicator of sexual and reproductive health²2 Abramovay M, Castro MG, Silva LB. Juventude e sexualidade. Brasília: UNESCO Brasil; 2004.. It generally takes place between 15 and 19 years of age in Latin America’s population³3 World Health Organization (WHO). The changing world of adolescent sexual and reproduc tive health and rights. Departmental news Reading. Geneva: WHO; 2020.^,44 Cabral CS, Brandão ER. Gravidez na adolescência, iniciação sexual e gênero: perspectivas em disputa. Cad Saude Publica 2020; 36(8):e00029420.. However, sexual and reproductive behavior of adolescents aged 10 to 14, an age period called early adolescence¹1 World Health Organization (WHO). The Sexual and Reproductive Health of Younger Adolescents: Research Issues in Developing Countries. Geneva: WHO; 2011., has also been an object of research and the target of health care policies in several countries⁴4 Cabral CS, Brandão ER. Gravidez na adolescência, iniciação sexual e gênero: perspectivas em disputa. Cad Saude Publica 2020; 36(8):e00029420.^,55 Organização Mundial da Saúde (OMS). INSPIRE: sete estratégias para pôr fim à violência contra crianças. Núcleo de Estudos da Violência. Genebra: OMS; 2018.. That interest increased considerably after the International Conference on Population and Development (ICPD) in 1994⁶6 Fundo de População das Nações Unidas (UNFPA Brasil). Relatório da Conferência Internacional sobre População e Desenvolvimento [Conferência do Cairo]. Brasília: UNFPA Brasil; 2007., which considered this part of the population one of the most vulnerable groups regarding the violation of their fundamental rights, since part of sexual relations in this age group are not consensual, but rather abusive in nature⁷7 Finer LB, Philbin JM. Trends in ages at key reproductive transitions in the United States, 1951-2010. Womens Health Issues 2014; 24:e271-9.^,88 Brasil. Ministério da Saúde (MS). Saúde Brasil 2017: uma análise da situação de saúde e os desafios para o alcance dos objetivos de desenvolvimento sustentável. Brasília: MS; 2018..

To understand the sexual and reproductive behavior of adolescents and young people, this topic has to be addressed in a multidimensional and contextualized manner, considering ecological systems in which different factors that are related to society, the community and individual relationships interact with each other⁹9 Markham CM, Rushing SC, Jessen C, Lane TL, Gorman G, Gaston A, Revels TK, Torres J, Williamson J, Baumler ER, Addy RC, Peskin MF, Shegog R. Factors Associated With Early Sexual Experience Among American Indian and Alaska Native Youth. J Adolesc Health 2015; 57(3):334-341.^,1010 Woog V, Kågesten A. The Sexual and Reproductive Health Needs of Very Young Adolescents Aged 10-14 in Developing Countries:What Does the Evidence Show? New York: Guttmacher Institute; 2017.. Factors such as Western culture, which is rooted in the patriarchal model, influence how society addresses that issue and distinguishes its approach and guidance on sexual behavior, including differences between genders³3 World Health Organization (WHO). The changing world of adolescent sexual and reproduc tive health and rights. Departmental news Reading. Geneva: WHO; 2020.^,1010 Woog V, Kågesten A. The Sexual and Reproductive Health Needs of Very Young Adolescents Aged 10-14 in Developing Countries:What Does the Evidence Show? New York: Guttmacher Institute; 2017.^,1111 Silva ASN, Silva BL Costa N, Silva JAF, Silva MCF, Guerreiro JF, Sousa ASCA. Início da vida sexual em adolescentes escolares: um estudo transversal sobre comportamento sexual de risco em Abaetetuba, Estado do Pará, Brasil. Rev Panamazonica Saude 2015; 6(3):27-34.. As previous studies point out, men often start sex life earlier and are encouraged to be independent and courageous. In that context, sexual practice is as an act related to the opportunity and affirmation of their masculinity, while women attribute an affective-loving sense to relationships and have a rather romanticized view of sexual relations³3 World Health Organization (WHO). The changing world of adolescent sexual and reproduc tive health and rights. Departmental news Reading. Geneva: WHO; 2020.^,44 Cabral CS, Brandão ER. Gravidez na adolescência, iniciação sexual e gênero: perspectivas em disputa. Cad Saude Publica 2020; 36(8):e00029420.^,1111 Silva ASN, Silva BL Costa N, Silva JAF, Silva MCF, Guerreiro JF, Sousa ASCA. Início da vida sexual em adolescentes escolares: um estudo transversal sobre comportamento sexual de risco em Abaetetuba, Estado do Pará, Brasil. Rev Panamazonica Saude 2015; 6(3):27-34.

12 Costa SF, Taquette SR, Moraes CL, Luciana MBMS, Moura MP. Contradições acerca da violência sexual na percepção de adolescentes e sua desconexão da lei que tipifica o "estupro de vulnerável". Cad Saude Publica 2020; 36(11):e00218019.^-1313 Minayo MCS, Assis SG, Njaine K, organizadores. Amor e violência: um paradoxo das relações de namoro e do 'ficar' entre jovens brasileiros. Rio de Janeiro: Fiocruz; 2011..

In Brazil, the debate on sexual and reproductive behavior is still surrounded by taboos, which may reflect its conservative approach to developing sexual and reproductive health education proposals⁴4 Cabral CS, Brandão ER. Gravidez na adolescência, iniciação sexual e gênero: perspectivas em disputa. Cad Saude Publica 2020; 36(8):e00029420.^,1111 Silva ASN, Silva BL Costa N, Silva JAF, Silva MCF, Guerreiro JF, Sousa ASCA. Início da vida sexual em adolescentes escolares: um estudo transversal sobre comportamento sexual de risco em Abaetetuba, Estado do Pará, Brasil. Rev Panamazonica Saude 2015; 6(3):27-34.. The topic was gradually included in health and educational sectors from the 1960s according to a hygienist logic, in the perspective of “scientia sexualis”¹⁴14 Foucault M. História da sexualidade I: a vontade de saber. Rio de Janeiro: Graal; 1985.^,1515 Nardi HC, Quartiero E. Educando para a diversidade: desafiando a moral sexual e construindo estratégias de combate à discriminação no cotidiano escolar. Sex Salud Soc (Rio J) 2012; 11:59-87.. During the 1980s/1990s, due to social movements, the HIV/AIDS epidemic and the context of Brazil’s redemocratization, debates made some progress, it became an interdisciplinary topic and was related to others in the proposal of the National Curriculum Parameters of 1995¹⁵15 Nardi HC, Quartiero E. Educando para a diversidade: desafiando a moral sexual e construindo estratégias de combate à discriminação no cotidiano escolar. Sex Salud Soc (Rio J) 2012; 11:59-87.^,1616 Brasil. Secretaria de Educação Fundamental. Parâmetros Curriculares Nacionais: introdução aos parâmetros curriculares nacionais. Brasília: MEC/SEF; 1997.. However, despite these advances, the current public policy proposals tend to encourage postponement/abstinence from sexual life as a strategy to prevent teenage pregnancy⁴4 Cabral CS, Brandão ER. Gravidez na adolescência, iniciação sexual e gênero: perspectivas em disputa. Cad Saude Publica 2020; 36(8):e00029420.^,1717 Brasil. Lei nº 13.798, de 3 de janeiro de 2019. Acrescenta art. 8º-A à Lei nº 8.069, de 13 de julho de 1990 (Estatuto da Criança e do Adolescente), para instituir a Semana Nacional de Prevenção da Gravidez na Adolescência. Diário Oficial da União 2019; 4 jan., which has been criticized for diverging from the struggle to ensure the sexual and reproductive rights of this population³3 World Health Organization (WHO). The changing world of adolescent sexual and reproduc tive health and rights. Departmental news Reading. Geneva: WHO; 2020.^,44 Cabral CS, Brandão ER. Gravidez na adolescência, iniciação sexual e gênero: perspectivas em disputa. Cad Saude Publica 2020; 36(8):e00029420.. Regarding the subgroup of adolescents aged 10 to 14, the debate is even more complex due to legal issues addressed by the Brazilian Penal Code¹⁸18 Brasil. Lei nº 12.015, de 7 de agosto de 2009. Altera o Título VI da Parte Especial do Decreto-Lei no 2.848, de 7 de dezembro de 1940 - Código Penal, e o art. 1o da Lei no 8.072, de 25 de julho de 1990, que dispõe sobre os crimes hediondos, nos termos do inciso XLIII do art. 5o da Constituição Federal e revoga a Lei no 2.252, de 1o de julho de 1954, que trata de corrupção de menores. Diário Oficial da União 2009; 10 out. and alarmist discourses about teenage pregnancy. According to data by the Ministry of Health, Brazil counted 3.2 million adolescent mothers between 2011 and 2016, 162,853 (5%) of which belonged to the 10-14 age group¹⁹19 Brasil. Ministério da Saúde (MS). Saúde Brasil 2015/2016: uma análise da situação de saúde e da epidemia pelo vírus Zika e por outras doenças transmitidas pelo Aedes aegypti. Brasília: MS; 2017..

Scientific literature shows that during early adolescence, i.e. the stage of life from 10 to 14 years of age, sexual initiation usually occurs in contexts of greater vulnerability, such as in lower social classes¹⁰10 Woog V, Kågesten A. The Sexual and Reproductive Health Needs of Very Young Adolescents Aged 10-14 in Developing Countries:What Does the Evidence Show? New York: Guttmacher Institute; 2017.^,2020 Hugo TD, Maier OVT, Jansen K, Rodrigues CEG, Cruzeiro ALS, Ores LC, Pinheiro RT, Silva R, Souza LDM. Fatores associados à idade da primeira relação sexual em jovens: estudo de base populacional, Cad Saude Publica 2011; 27(11):2207-2214.. It is accompanied by health risk behaviors, such as alcohol/drug use, takes place among individuals who are involved with several partners, individuals who resort to unprotected sexual practices and those who lack sufficient knowledge on contraceptive methods²¹21 Conduct Problems Prevention Research Group. Trajectories of Risk for Early Sexual Activity and Early Substance Use in the Fast Track Prevention Program. Prev Sci 2014; 15:33-46.^,2222 Lara LAS, Abdo CHN. Aspectos da atividade sexual precoce. Rev Bras Ginecol Obstet 2015; 37(5):199-202.. Some authors suggest that these factors, among others, expose this group to a higher risk of sexually transmitted infections (STIs), teenage pregnancy and maternal death⁵5 Organização Mundial da Saúde (OMS). INSPIRE: sete estratégias para pôr fim à violência contra crianças. Núcleo de Estudos da Violência. Genebra: OMS; 2018.^,1010 Woog V, Kågesten A. The Sexual and Reproductive Health Needs of Very Young Adolescents Aged 10-14 in Developing Countries:What Does the Evidence Show? New York: Guttmacher Institute; 2017.^,2121 Conduct Problems Prevention Research Group. Trajectories of Risk for Early Sexual Activity and Early Substance Use in the Fast Track Prevention Program. Prev Sci 2014; 15:33-46.

22 Lara LAS, Abdo CHN. Aspectos da atividade sexual precoce. Rev Bras Ginecol Obstet 2015; 37(5):199-202.

23 Amorim MMR, Lima LA, Lopes CV, Araújo DKL, Silva JGG, César LC, Melo ASO. Fatores de risco para a gravidez na adolescência em uma maternidade-escola da Paraíba: estudo caso-controle. Rev Bras Ginecol Obstet 2009; 31(8):404-410.^-2424 Gonçalves H, Machado EC, Soares ALG, Camargo-Figuera FA, Seerig LM, Mesenburg MA, Guttier MC, Barcelos RS, Buffarini R, Assunção MCF, Hallal PC, Menezes AMB. Início da vida sexual entre adolescentes (10 a 14 anos) e comportamentos em saúde. Rev Bras Epidemiol 2015; 18(1):499-506.. However, Cabral and Brandão⁴4 Cabral CS, Brandão ER. Gravidez na adolescência, iniciação sexual e gênero: perspectivas em disputa. Cad Saude Publica 2020; 36(8):e00029420. emphasize that these factors may increase the incidence of sexually transmitted infections (STIs) and unplanned pregnancies in any age group and are thus not a condition that may be associated exclusively with early adolescence.

Given the controversial nature of that discussion, different initiatives aimed at the sexual and reproductive education of adolescents have been adopted by several countries. Some emphasize “sexual majority”, such as the UK, which deems that maturity to practice autonomy safely is only achieved at the age of 16²⁵25 National Society for the Prevention of Cruelty to Children (NSPCC). Gillick competency and Frazer guidelines [Internet]. [cited 2021 out 23]. Available from: https://learning.nspcc.org.uk/child-protection-system/gillick-competence-fraser-guidelines.
https://learning.nspcc.org.uk/child-prot... . The USA invests in intervention programs²⁶26 Kaufman CE, Rumbaugh WN, Keane E, Desserich JA, Giago C, Sam A, Mitchell CM. Effectiveness of circle of life, an HIV- preventive intervention for American Indian middle school youths: A group randomized trial in a Northern Plains tribe. Am J Public Health 2014; 104:e106e12. and in Brazil, the Programa Saúde na Escola (PSE) [Health at School Program]²⁷27 Brasil. Ministério da Saúde (MS). Passo a passo PSE: Programa Saúde na Escola: tecendo caminhos da intersetorialidade. Brasília: MS; 2011. - despite being intersectoral - has developed some activities, although in a fragmented way and unrelated to legislation¹⁷17 Brasil. Lei nº 13.798, de 3 de janeiro de 2019. Acrescenta art. 8º-A à Lei nº 8.069, de 13 de julho de 1990 (Estatuto da Criança e do Adolescente), para instituir a Semana Nacional de Prevenção da Gravidez na Adolescência. Diário Oficial da União 2019; 4 jan.^,1818 Brasil. Lei nº 12.015, de 7 de agosto de 2009. Altera o Título VI da Parte Especial do Decreto-Lei no 2.848, de 7 de dezembro de 1940 - Código Penal, e o art. 1o da Lei no 8.072, de 25 de julho de 1990, que dispõe sobre os crimes hediondos, nos termos do inciso XLIII do art. 5o da Constituição Federal e revoga a Lei no 2.252, de 1o de julho de 1954, que trata de corrupção de menores. Diário Oficial da União 2009; 10 out.. Further research is still needed to better understand the situations and intervene more effectively to meet the proposals of the “Global Strategy” and of the 2030 Agenda for Sustainable Development that advocate universal access to health, including sexual and reproductive health of adolescents¹⁰10 Woog V, Kågesten A. The Sexual and Reproductive Health Needs of Very Young Adolescents Aged 10-14 in Developing Countries:What Does the Evidence Show? New York: Guttmacher Institute; 2017.^,2828 Pan American Health Organization (PAHO). Organização Mundial da Saúde (OMS). Plano de ação para a saúde da mulher, da criança e do adolescente 2018-2030. 56º Conselho Diretor 70ª Sessão do Comitê Regional da OMS para as Américas. Washington D.C.: PAHO, OMS; 2018..

It is essential to know the percentage and features of adolescents and young people who started sexual life during early adolescence to better plan strategies that promote sexual and reproductive education to strengthen young people’s autonomy and empowerment based on a context of intersectorality⁵5 Organização Mundial da Saúde (OMS). INSPIRE: sete estratégias para pôr fim à violência contra crianças. Núcleo de Estudos da Violência. Genebra: OMS; 2018.^,1010 Woog V, Kågesten A. The Sexual and Reproductive Health Needs of Very Young Adolescents Aged 10-14 in Developing Countries:What Does the Evidence Show? New York: Guttmacher Institute; 2017.. Analyzing differences between those estimates in the different population subgroups by considering gender, school type and other risk factors of sexual initiation in early adolescence may help develop more effective interventions aimed at conscious and safe sexual practice⁵5 Organização Mundial da Saúde (OMS). INSPIRE: sete estratégias para pôr fim à violência contra crianças. Núcleo de Estudos da Violência. Genebra: OMS; 2018.^,1010 Woog V, Kågesten A. The Sexual and Reproductive Health Needs of Very Young Adolescents Aged 10-14 in Developing Countries:What Does the Evidence Show? New York: Guttmacher Institute; 2017.^,2121 Conduct Problems Prevention Research Group. Trajectories of Risk for Early Sexual Activity and Early Substance Use in the Fast Track Prevention Program. Prev Sci 2014; 15:33-46.. Based on this perspective, this study aims to estimate the prevalence of sexual initiation between 10 and 14 years and to identify subgroups that are more vulnerable to the situation among public and private school pupils of the IX Administrative Region of the city of Rio de Janeiro, Brazil.

Methods

Study design and scenario

This is a sub-project of a school-based cross-sectional study entitled “Rape of a vulnerable person and other forms of violence against female adolescents” - research funded by the Fundação Carlos Chagas Filho de Amparo à Pesquisa do Estado do Rio de Janeiro (FAPERJ) (Call FAPERJ nº 30/2014). The study scenario included the public and private schools of the IX Administrative Region (AR) of the city of Rio de Janeiro. The IX AR covers four neighborhoods of the city of Rio de Janeiro: Vila Isabel, Andaraí, Grajaú and Maracanã. According to the 2010 Brazilian census²⁹29 Instituto Pereira Passos (IPP) [Internet]. 2020 [acessado 2021 out 23]. Disponível em: https://www.data.rio/.
https://www.data.rio... , this region counts approximately 190,000 inhabitants with an average per capita income of BRL 1,836 (USD 1,020 at the time). Families of all socioeconomic levels have lived in that region, in luxury buildings, medium-sized houses and clandestine settlements/favelas³⁰30 Prefeitura da cidade do Rio de Janeiro [Internet]. [acessado 2021 out 23]. Disponível em: http://www.rio.rj.gov.br/dlstatic/10112/1529762/dlfe-220205.pdf/1.0.
http://www.rio.rj.gov.br/dlstatic/10112/... .

Selection strategy and sample size

In the study period, the IX AR of Rio de Janeiro totaled 1,470 pupils who were distributed in 52 classes and were regularly enrolled in the second high-school year in five public schools (714 pupils) and fifteen private schools (756 pupils). The study population was selected through a complex sampling procedure including cluster-based and stratified sampling and by taking into account school types (public or private) and course types (daytime or evening courses). Class selection probability was proportional to school size and all pupils from selected classes were invited to participate in the research. Among the 747 pupils eligible for the background study, 721 (95.4%) agreed to participate in the research. Of these, 94.4 % (717) were aged between 15 and 24 and were thus eligible for the present study. Additional exclusion criteria included: a) Pupils whose sexual initiation took place before the age of 10 (n=2) and b) Pupils of Asian (n=7) or Indigenous (n=14) descent, given the reduced number of participants in these population subgroups, which would hamper more robust estimates of the prevalence of sexual initiation in early adolescence in these individuals. The final sample of this study consisted of 694 participants.

Data collection and measurement instruments

Data were collected between September 2016 and February 2017 in classrooms using a multidimensional structured autocomplete questionnaire whose application was supervised by a previously trained field team.

The most important variable was the occurrence of sexual initiation during early adolescence, i.e., between 10 and 14 years of age. That information was obtained by a direct question on pupils’ age at their first sexual intercourse. “Sexual initiation” included positive answers to a structured yes/no-question: “Have you ever had sexual intercourse?”. If a participant’s first sexual intercourse had occurred between 10 to 14 years of age, he/she was considered to have had “sexual initiation in early adolescence”.

The variable race/skin color was created based on the classification of the Brazilian Institute of Geography and Statistics (IBGE). We chose to include only two categories: Whites and the combination Blacks/Browns, who were considered as belonging to the same ethnic group. Gender was classified as either male or female and religion as the participant’s current one, which was later categorized as having or not having a religion at the time of the interview. Variables “maternal education” and “family purchasing power” were categorized by means of Brazil’s Economic Classification Criterion (CCEB), version 2015³¹31 Associação Brasileira de Empresas de Pesquisa (ABEP). Critério Padrão de Classificação Econômica Brasil. São Paulo: ABEP; 2017. and were measured to characterize the family’s socioeconomic status. Originally, the CCEB classifies families in seven categories (A, B1, B2, C1, C2, D and E), where Class A represents the highest and Class E the lowest purchasing power. In the participant profile description, classes “D” and “E” were grouped. To study the prevalence of sexual initiation during early adolescence in the different population subgroups, classes “A” and “B” were also grouped. In both analyses, categories B1 and B2 and C1 and C2 were grouped into B and C, respectively.

Family structure features were identified through the context of parenthood, based on whether the pupils’ parents were alive or deceased. Cohabitation informed us about who the participant was living with at the time of the study. To identify the maternal background of teenage pregnancy, the pupil’s age was subtracted from the mother’s age at the time of the interview. This variable was called “mother’s age at the birth of the child” and was divided into the following age groups: 10 to 19 years, 20 to 34 years, 35 years and older. School features included school type (public x private) and course type (daytime x evening).

Information on features of sexual initiation, the path of affective-sexual relationships and sexual violence in affective-sexual relationships were identified through structured questions that allowed to identify: age at first sexual intercourse, degree of commitment between peers, such as “hooking up”, “dating”, and same-sex sexual experience. Those data were obtained by means of the following questions: “Have you ever ‘hooked up’ or had any non-commitment love relationship with someone?” and “Have you ever dated someone?”. Pupils who answered “yes” to any of these questions were asked how old they were when that kind of relationship first occurred. Classification of individuals according to same-sex sexual experience was based on the question “Have you ever had a sexual experience/intimate contact with a person of the same sex?”. All of these variables were “Yes/No” questions.

Information on sexual victimization in affective-sexual relations was obtained by means of the Portuguese version of the Conflict in Adolescent Dating Relationships Inventory (CADRI), created by Wolfe et al.³²32 Wolfe DA, Scott K, Reitzel-Jaffe D, Wekerle C, Grasley C, Straatman AL. Development and validation of the Conflict in Adolescent Dating Relationships Inventory. Psychol Assess 2001; 13(2):277-293. and initially adapted and validated for its use in Brazil by Minayo et al.¹³13 Minayo MCS, Assis SG, Njaine K, organizadores. Amor e violência: um paradoxo das relações de namoro e do 'ficar' entre jovens brasileiros. Rio de Janeiro: Fiocruz; 2011.. The version of the instrument we used contains 28 items, 25 of which refer to the various forms of violence in dating, such as emotional violence, physical violence, sexual violence, relational violence and threat. This study merely used the victimization of sexual violence subscale, which only takes into account events that took place in the last twelve months. Sexual violence was deemed present if at least one item of the above-mentioned subscale showed a positive answer.

The use of substances such as alcohol, tobacco and marijuana in the last three months was evaluated as binary “Yes/No” variables using The Alcohol, Smoking and Substance Involvement Screening Test (ASSIST) by the World Health Organization (WHO)³³33 Organização Mundial da Saúde (OMS). Questionário para Triagem do Uso de Álcool, tabaco e Outras Substâncias. ASSIST [Internet]. [acessado 2021 out 23]. Disponível em: https://www.who.int.
https://www.who.int... .

Data analysis

Prevalence of sexual initiation during early adolescence, as well as its 95% confidence intervals (95%CI) were estimated in the total population and in the groups of male and female adolescents. A Chi-Square test (χ2) was performed to evaluate the heterogeneity of the proportions of the population subgroups and a p-value<0.05 was adopted to identify statistically significant differences. The co-occurrence profile between adoption of risk behavior and violence during dating among boys and girls with and without sexual initiation in early adolescence was plotted using the Venn Diagram. Adoption of risk behavior included misuse of alcohol, tobacco and marijuana. All analyzes took into account the complex sampling structure and were performed by means of the Stata 13 software program³⁴34 StataCorp. Stata Statistical Software [computer program]. Release 13. College Station: StataCorp LP; 2013..

Ethical aspects

The study met all ethical standards of Resolution 466/2012 by the National Health Council and was approved by the Research Ethics Committee (CEP) of the University of the State of Rio de Janeiro (UERJ) on 09/18/2015, CAAE by decree No. 48107514.2.0000.5282 and approved by the State Department of Education of Rio de Janeiro.

Results

Table 1 shows that 53.3% of the participants were females, most of which were between 15 and 18 years old; 53.2% declared to be white and 65.3% attended some religious institution at the time of this research. Regarding the socioeconomic situation of their families, a large part (45%) were children of mothers who had a high-school or academic degree and belonged to Economic Class B. More than 80% reported that their parents were alive and only few of them did not know or had never met their father (9.0%).

Regarding family arrangements, almost 80% were living with either both their parents or one parent and 13.5% showed a background of maternal teenage pregnancy. More than 60% of the pupils attended private schools, mostly daytime courses. There was no statistically significant difference in the distribution of these features according to gender, except for religious practice, whose percentage was slightly higher among girls (Table 1).

Table 2 shows the features of the population studied in relation to the context of sexual initiation, the paths of affective-sexual relationships and health risk behaviors. It shows that 18.4% of the participants were sexually initiated during early adolescence and that half of the total study population started their affective/love path at that age as well, including the “hooking up” and “dating” modalities. Approximately 17% reported having had a same-sex sexual experience and 40% of them responded positively to at least one of the items that make up the scale of sexual victimization in dating. More than 70% of them claimed to have consumed alcohol, just over 22% tobacco and approximately 20% marijuana. Analysis of prevalence according to gender showed that sexual initiation during early adolescence was twice as high in boys than in girls (25.7% x 12.2%) and a sexual experience with a person of the same sex was more often reported by girls.

Table 3 reveals that sexual initiation during early adolescence was more frequent among pupils whose mothers had a lower educational level. Regarding school features, there was a higher percentage among pupils from public schools and evening courses. There are some differences between boys and girls as well. Sexual initiation during early adolescence was more frequent among girls from “D” and “E” social classes, among those who had only one parent or none alive and among those whose mothers were adolescent at the time their daughters were born. Those features seem to be unrelated to the age of sexual initiation of the boys.

The prevalence of the event was also analyzed according to the features of their affective-sexual relationship path and health risk behaviors (Table 4). The prevalence was higher among those who claimed to have hooked up/dated before the age of 15; among those who mentioned victimization of sexual violence in affective-sexual relations in the last twelve months; and among those who used substances such as alcohol, tobacco, and marijuana in the last three months. If we focus on the male population alone, the above-mentioned features repeat themselves, while the prevalence was not higher among those who report alcohol use among girls.

Figure 1 shows that most adolescents and young people accumulate different risk behaviors and sexual victimization in their affective-sexual relationships. Accumulation of vulnerabilities occurs especially in boys whose sexual initiation took place between 10 and 14 years of age.

Discussion

Study results show that the sexarche of about 1/5 of the participants took place during early adolescence, which is reported twice as much by boys than by girls. These results are similar to those found by Gonçalves et al.²⁴24 Gonçalves H, Machado EC, Soares ALG, Camargo-Figuera FA, Seerig LM, Mesenburg MA, Guttier MC, Barcelos RS, Buffarini R, Assunção MCF, Hallal PC, Menezes AMB. Início da vida sexual entre adolescentes (10 a 14 anos) e comportamentos em saúde. Rev Bras Epidemiol 2015; 18(1):499-506. who conducted a survey of 4,325 adolescents from a birth cohort in Pelotas, Rio Grande do Sul, Brazil, which found that 18.6% of the adolescents went through sexual initiation before the age of 15 (20.9% of the boys and 16.4% of the girls). However, our study shows a greater difference between boys and girls. A similar profile was found by the 2015 National School Health Survey (PeNSE)³⁵35 Instituto Brasileiro de Geografia e Estatística (IBGE). Pesquisa nacional de saúde do escolar: 2015. Rio de Janeiro: IBGE; 2016., according to which 27.0% of the 13-15-year-old pupil subgroup reported having had sexual intercourse in the past (34.5% of the boys and 19.3% of the girls). Those findings corroborate the idea of gender asymmetry in the sexual and reproductive health area, regardless of the fact that male puberty takes place later than the female one.

Sexual initiation during early adolescence was also more frequent in pupils of subgroups inserted in contexts of greater social vulnerability. PeNSE 2015’s³⁵35 Instituto Brasileiro de Geografia e Estatística (IBGE). Pesquisa nacional de saúde do escolar: 2015. Rio de Janeiro: IBGE; 2016. results had already drawn the attention to that profile as they show that 29.7% of the public school pupils went through sexual initiation before the age of 15, against only 15.0% of the private school pupils. The nature of this study did not allow us to investigate what caused the large gap between public and private schools or between daytime and evening course. However, pupils who attend public school evening courses accumulate additional social disadvantages, as they belong to low-income families, have a lower educational level and are inserted in the labor market performing low-wage jobs.

Living with adults in charge also seems to postpone sexarche. PeNSE (2009) data analysis shows that 42.1% of the pupils who do not live with their parents had sexual intercourse at some point in the past, against only 26.6% of the pupils who live with their parents³⁶36 Malta DC, Silva MAI, Mello FCM, Monteiro RA, Porto DL, Sardinha LMV, Freitas PC. Saúde sexual dos adolescentes segundo a pesquisa nacional de saúde dos escolares. Rev Bras Epidemiol 2011; 14(Supl. 1):147-156.. In our study, although the frequency was twice as high among girls who had either no contact with their father or no living father, this difference was not statistically significant. Maternal teenage pregnancy background has also been addressed by the literature as a bond of identification and connection, especially between mothers and daughters, which suggests that sexual and reproductive background repeats itself across generations²³23 Amorim MMR, Lima LA, Lopes CV, Araújo DKL, Silva JGG, César LC, Melo ASO. Fatores de risco para a gravidez na adolescência em uma maternidade-escola da Paraíba: estudo caso-controle. Rev Bras Ginecol Obstet 2009; 31(8):404-410.^,2424 Gonçalves H, Machado EC, Soares ALG, Camargo-Figuera FA, Seerig LM, Mesenburg MA, Guttier MC, Barcelos RS, Buffarini R, Assunção MCF, Hallal PC, Menezes AMB. Início da vida sexual entre adolescentes (10 a 14 anos) e comportamentos em saúde. Rev Bras Epidemiol 2015; 18(1):499-506.^,3737 Dias ACG, Teixeira MAP. Gravidez na adolescência: um olhar sobre um fenômeno complexo. Paideia (Ribeirão Preto) 2010; 20(45):123-131.^,3838 Dias AB, Aquino EML. Maternidade e paternidade na adolescência: algumas constatações em três cidades do Brasil. Cad Saude Publica 2006; 22(7):1447-1458.. The study by Gonçalves et al.²⁴24 Gonçalves H, Machado EC, Soares ALG, Camargo-Figuera FA, Seerig LM, Mesenburg MA, Guttier MC, Barcelos RS, Buffarini R, Assunção MCF, Hallal PC, Menezes AMB. Início da vida sexual entre adolescentes (10 a 14 anos) e comportamentos em saúde. Rev Bras Epidemiol 2015; 18(1):499-506. also showed that the earlier the mother’s pregnancy occurred, the higher the prevalence of sexual initiation in early adolescence in the next generation. According to the authors, 42.9% of the girls whose mothers got pregnant by the age of 14 also went through sexual initiation during early adolescence, while only 20.9% of the girls whose mothers got pregnant between 15 and 19 had their first sexual contact before the age of 15. It is worth noting that this trend did not occur among boys, which corroborates Dias and Teixeira’s³⁷37 Dias ACG, Teixeira MAP. Gravidez na adolescência: um olhar sobre um fenômeno complexo. Paideia (Ribeirão Preto) 2010; 20(45):123-131. statement that intergenerational transmission only takes place in mothers and daughters. A multi-centric study that was conducted in three Brazilian cities (GRAVAD research) and involved approximately 4,600 subjects aged 18 to 24 years also mentions that the maternal teenage pregnancy background repeats itself in girls only³⁸38 Dias AB, Aquino EML. Maternidade e paternidade na adolescência: algumas constatações em três cidades do Brasil. Cad Saude Publica 2006; 22(7):1447-1458..

It is important to highlight that the differences between subgroups according to the vulnerability profile of families were especially visible in girls. Those, when inserted in a family context of greater social vulnerability such as low-income families, low maternal education, dissolution of the two-parent family and a maternal adolescent pregnancy background, began having sexual contacts at an earlier age.

Data on participants’ affective-sexual relationship path help understand the context of sexual initiation of adolescents and young people¹³13 Minayo MCS, Assis SG, Njaine K, organizadores. Amor e violência: um paradoxo das relações de namoro e do 'ficar' entre jovens brasileiros. Rio de Janeiro: Fiocruz; 2011.. A study on factors associated with sexual initiation involving 427 mothers aged 14 to 16 from Porto Alegre-RS, Brazil shows that casual partnerships increased the prevalence of sexual initiation in early adolescence by 28%³⁹39 Spinola MCR, Béria JU, Schermann LB. Fatores associados à iniciação sexual em mães de 14 a 16 anos em Porto Alegre/RS, Brasil. Cien Saude Colet 2017; 22(11):3755-3762.. Study results also show a higher prevalence of sexual initiation during early adolescence among girls who reported sexual victimization in affective-sexual relationships in the last 12 months. Thus, it is essential to include the discussion on violence in affective-sexual relationships among adolescents to characterize the profile of individuals who are having their first sexual experience before the age of 14¹⁰10 Woog V, Kågesten A. The Sexual and Reproductive Health Needs of Very Young Adolescents Aged 10-14 in Developing Countries:What Does the Evidence Show? New York: Guttmacher Institute; 2017.. It is extremely relevant to prioritize that issue due to the evidence that points to a higher risk of violence in the first affective-sexual relationships¹⁰10 Woog V, Kågesten A. The Sexual and Reproductive Health Needs of Very Young Adolescents Aged 10-14 in Developing Countries:What Does the Evidence Show? New York: Guttmacher Institute; 2017., its serious negative consequences to health and because these experiences may turn into risk factors for victimization at other life stages¹³13 Minayo MCS, Assis SG, Njaine K, organizadores. Amor e violência: um paradoxo das relações de namoro e do 'ficar' entre jovens brasileiros. Rio de Janeiro: Fiocruz; 2011..

Use of substances such as tobacco, alcohol and illicit drugs has often been highlighted in the literature as part of health risk behaviors associated with a decrease in the age of the first sexual intercourse²⁰20 Hugo TD, Maier OVT, Jansen K, Rodrigues CEG, Cruzeiro ALS, Ores LC, Pinheiro RT, Silva R, Souza LDM. Fatores associados à idade da primeira relação sexual em jovens: estudo de base populacional, Cad Saude Publica 2011; 27(11):2207-2214. and the use of illicit drugs and tobacco in the last three months. However, unlike our findings, the authors found no association between the event and the use of alcoholic beverages in this period. Our study also identified a high number of adolescents and young people who had their first sexual experience in early adolescence among those who made use of these substances. Results show that a good part of adolescents and young people whose sexual initiation took place during early adolescence and used substances also reported some degree of sexual violence in their love relationships. If we combine this information with the fact that many of these pupils belong to families of a low socioeconomic status, who lack a father figure, whose mothers became pregnant during adolescence, that they and are inserted in the labor market performing low-wage jobs and therefore have to study in the evening, we find that these adolescents accumulate numerous factors that explain their social vulnerability²²22 Lara LAS, Abdo CHN. Aspectos da atividade sexual precoce. Rev Bras Ginecol Obstet 2015; 37(5):199-202.^,4040 Silva KS, Rozenberg R, Bonan C, Chuva VCC, Costa SF, Gomes MASM. Gravidez recorrente na adolescência e vulnerabilidade social no Rio de Janeiro (RJ, Brasil): uma análise de dados do sistema de nascidos vivos. Cien Saude Colet 2011; 16(5):2485-2493..

Simultaneous occurrence and accumulation of vulnerabilities has been reported by several authors. The relationship between alcohol/drug misuse and dating violence, e.g., has also been mentioned by O’Keefe⁴¹41 O'Keefe M. Predictors of dating violence among high school students. J Interpers Violence 1997; 12(4):546-568. and by Shorey et al.⁴²42 Shorey RC, Stuart GL, Cornelius TL. Dating violence and substance use in college students: A review of the literature. Aggress Violent Behav 2011; 16(6):541-550.. Audi et al.⁴³43 Audi CAF, Segall-Corrêa AM, Santiago SM, Andrade MGG, Escamila RP. Violência doméstica na gravidez: prevalência e fatores associados. Rev Saude Publica 2008; 42(5):877-885. also show that a first pregnancy before the age of 16, as well as the partner’s use of tobacco, alcohol or illicit drugs are associated with victimization of physical/sexual violence committed by intimate partners of pregnant women who attended prenatal care at a public health clinic in Campinas-SP, Brazil. A longitudinal study conducted in US schools involving 1,199 pupils with childhood behavior issues and/or family adversities took into account three risk behavior indicators, i.e., sexual initiation between 13 and 14 years of age, use of tobacco, and use of alcohol/drugs concluded that these behaviors belong together and are important high-risk factors of other adverse situations, such as teenage pregnancy and sexually transmitted infections²¹21 Conduct Problems Prevention Research Group. Trajectories of Risk for Early Sexual Activity and Early Substance Use in the Fast Track Prevention Program. Prev Sci 2014; 15:33-46..

The results of this study need to be interpreted in light of its limitations and strengths. Regarding limitations, it is noteworthy that the definition of cases of sexual initiation in early adolescence was based exclusively on the answer to the direct question on having had “sexual relations”. Participants may interpret “sexual relation” in different ways, according to their social, moral, religious and cultural background. In this sense, cases involving other forms of sexual expression without penetration, e.g. oral sex, may not have been considered. The lack of information on gender identity, age of menarche and other variables of reproductive background, such as number of partners and use of contraceptive methods are also limitations, since they would add to information on risk behavior. We suggest that these variables be considered in future studies on the topic.

Strengths of this study include a sufficiently large sample that allowed us to obtain quite accurate estimates and the study in subgroups. Another strength is the high representativeness of the study sample regarding the group of adolescents and young people attending high school in Rio de Janeiro, since it includes public and private school pupils from diverse city areas who were selected through probabilistic sampling. The use of consolidated autocomplete forms to identify situations of violence in dating and use of alcohol/drugs should also have increased the level of accuracy of our estimates. The wide range of features analyzed to build the profile of participants who had their first sexual contact by the age of 14, considering not only health risk behaviors usually included for this purpose, but also socioeconomic, cultural, family, and school aspects, as well as those related to affective-sexual relationships, provided a panoramic view of the factors related to the studied event, which is another positive point of our research.

Final considerations

Study results corroborate what has been pointed out by the literature, i.e., certain population subgroups start sexual life earlier than others. Those results also contribute to the debate on peculiarities of sexual and reproductive health of younger adolescents. It is essential to highlight that sexual initiation during early adolescence does not seem to be a problem situation as such if we take into account how relevant it is for adolescents and young people to learn about sexuality and build affective-sexual relationships. However, differences found among subgroups suggest that acquiring information and achieve maturity and autonomy in this area of life is not always equitable. The higher rate of sexual initiation at an early age among boys, among pupils from families with a lower socioeconomic status, among those who experience violence in affective-sexual relationships and those who assume health risk behaviors shows that this group is more vulnerable to adversity. That accumulation of risk situations implies that actions aimed at the full development of adolescents and young people need to be multi-thematic, intersectoral and take into account the specific features of every target public. In this sense, we emphasize the role of the school as a privileged space for socialization, acquisition of knowledge about sexuality and deconstruction of rigid social gender roles in affective-sexual relations. At the same time, we highlight how essential it is that actions that take place at schools interact with other social policies and the legislation to empower adolescents and young people in such a way that they may consciously decide when to start their sexual and reproductive life in an autonomous and safe way.

References

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