Predictors and Outcomes of Adolescents’ Sexual and Reproductive Health : An Ecological Approach

Experiences with sexual behaviors and intimate relationships typically start during adolescence. These experiences are a normative and integrated part of overall development, yet they may have consequences for adolescents’ sexual and reproductive health (SRH) and psychological wellbeing. Worldwide, estimates of the World Health Organization indicate that about 333 million sexually transmitted infections occur yearly, of which a considerable part affects adolescents aged 15–19 years. In addition, globally, about 17 million teenage girls younger than 20 years give birth every year. SRH problems among adolescents are a challenge for most countries, and are not restricted to low- and middle-income countries (LMIC). Understanding the factors that affect adolescents’ SRH behaviors and outcomes is a fundamental step towards the improvement of adolescents’ SRH. In the current thesis, we applied a holistic approach to understanding adolescent sexuality (ecological systems theory). The studies presented in this thesis investigate adolescents’ SRH behaviors and outcomes and various predictors thereof. Specifically, the SRH behaviors and outcomes included: adolescents’ experiences with early sexual behaviors, timing of first sexual intercourse, number of sexual partners, condom use, contraceptive use, and teen pregnancy. The predictors were classified into: 1) individual factors (e.g., gender, ethnic background, depression); 2) social factors (e.g., mother– and father–adolescent relationship quality, parental monitoring, in-school sexuality education). The studies described in this thesis illustrate the relevance of factors from diverse levels, from individual to social. Overall, our findings support that various stakeholders (e.g., parents, health professionals, and schools), and adolescents themselves, can contribute to a positive sexual development

Early sexual intercourse: Prospective associations with adolescents physical activity and screen time

Objectives: To assess the prospective associations of physical activity behaviors and screen time with early sexual intercourse initiation (i.e., before 15 years) in a large sample of adolescents. Methods: We used two waves of data from the Rotterdam Youth Monitor, a longitudinal study conducted in the Netherlands. The analysis sample consisted of 2,141 adolescents aged 12 to 14 years (mean age at baseline = 12.2 years, SD = 0.43). Physical activity (e.g., sports outside school), screen time (e.g., computer use), and early sexual intercourse initiation were assessed by means of self-report questionnaires. Logistic regression models were tested to assess the associations of physical activity behaviors and screen time (separately and simultaneously) with early sexual intercourse initiation, controlling for confounders (i.e., socio-demographics and substance use). Interaction effects with gender were tested to assess whether these associations differed significantly between boys and girls. Results: The only physical activity behavior that was a significant predictor of early sexual intercourse initiation was sports club membership. Adolescent boys and girls who were members of a sports club) were more likely to have had early sex (OR = 2.17; 95% CI = 1.33, 3.56. Significant gender interaction effects indicated that boys who watched TV ≥2 hours/ day (OR = 2.00; 95% CI = 1.08, 3.68) and girls who used the computer ≥2 hours/day (OR = 3.92; 95% CI = 1.76, 8.69) were also significantly more likely to have engaged in early sex. Conclusion: These findings have implications for professionals in general pediatric healthcare, sexual health educators, policy makers, and parents, who should be aware of these possible prospective links between sports club membership, TV watching (for boys), and computer use (for girls), and early sexual intercourse initiation. However, continued research on determinants of adolescents' early sexual initiation is needed to further contribute to the strategies for improving adolescents' healthy sexual development and behaviors

Longitudinal Associations Between Sexual Communication With Friends and Sexual Behaviors Through Perceived Sexual Peer Norms

The role of peers in adolescents’ sexual behaviors is not yet fully understood. We investigated the association between sexual communication with friends (at T1) and subsequent changes in adolescents’ experience with sexual behaviors (between T1–T3), and examined whether this association was explained by adolescents’ perceptions of three sexual peer norms (at T2): (1) peers’ se

Quantifying the relative importance of genetics and environment on the comorbidity between mental and cardiometabolic disorders using 17 million Scandinavians

Abstract Mental disorders are leading causes of disability and premature death worldwide, partly due to high comorbidity with cardiometabolic disorders. Reasons for this comorbidity are still poorly understood. We leverage nation-wide health records and near-complete genealogies of Denmark and Sweden (n = 17 million) to reveal the genetic and environmental contributions underlying the observed comorbidity between six mental disorders and 15 cardiometabolic disorders. Genetic factors contributed about 50% to the comorbidity of schizophrenia, affective disorders, and autism spectrum disorder with cardiometabolic disorders, whereas the comorbidity of attention-deficit/hyperactivity disorder and anorexia with cardiometabolic disorders was mainly or fully driven by environmental factors. In this work we provide causal insight to guide clinical and scientific initiatives directed at achieving mechanistic understanding as well as preventing and alleviating the consequences of these disorders

NEOTROPICAL CARNIVORES: a data set on carnivore distribution in the Neotropics

Mammalian carnivores are considered a key group in maintaining ecological health and can indicate potential ecological integrity in landscapes where they occur. Carnivores also hold high conservation value and their habitat requirements can guide management and conservation plans. The order Carnivora has 84 species from 8 families in the Neotropical region: Canidae; Felidae; Mephitidae; Mustelidae; Otariidae; Phocidae; Procyonidae; and Ursidae. Herein, we include published and unpublished data on native terrestrial Neotropical carnivores (Canidae; Felidae; Mephitidae; Mustelidae; Procyonidae; and Ursidae). NEOTROPICAL CARNIVORES is a publicly available data set that includes 99,605 data entries from 35,511 unique georeferenced coordinates. Detection/non-detection and quantitative data were obtained from 1818 to 2018 by researchers, governmental agencies, non-governmental organizations, and private consultants. Data were collected using several methods including camera trapping, museum collections, roadkill, line transect, and opportunistic records. Literature (peer-reviewed and grey literature) from Portuguese, Spanish and English were incorporated in this compilation. Most of the data set consists of detection data entries (n = 79,343; 79.7%) but also includes non-detection data (n = 20,262; 20.3%). Of those, 43.3% also include count data (n = 43,151). The information available in NEOTROPICAL CARNIVORES will contribute to macroecological, ecological, and conservation questions in multiple spatio-temporal perspectives. As carnivores play key roles in trophic interactions, a better understanding of their distribution and habitat requirements are essential to establish conservation management plans and safeguard the future ecological health of Neotropical ecosystems. Our data paper, combined with other large-scale data sets, has great potential to clarify species distribution and related ecological processes within the Neotropics. There are no copyright restrictions and no restriction for using data from this data paper, as long as the data paper is cited as the source of the information used. We also request that users inform us of how they intend to use the data