Introduction: Adolescent pregnancy and early initiation of sexual activity is a serious global public health problem, every year, around sixteen million adolescents between 15 and 19 years of age give birth, representing 11% of all births globally. Objective: To design a protocol of a pilot Randomized Controlled Trial to evaluate the preliminary efficacy of the "Be Yourself" intervention to increase self-determined motivation to prevent pregnancy in adolescents in secondary education. Methods: The protocol was developed based on the Protocol Items: ecommendations for Interventional Trials 2013 (SPIRIT2013) Statement, in the City of Monterrey, Nuevo León, Mexico in 2023. Results: The protocol outlined the design of the intervention, structured the content of the sessions using a logic model of intervention, and developed manuals for program facilitators and guides for participants. In addition, a website and a chatbot with Artificial Intelligence were developed, and the strategy for the application of the evaluation instruments was established. Conclusion: The educational intervention "Be yourself" is projected as a promising program to promote self-determined motivation and prevent adolescent pregnancy.

Background and Rationale Adolescent pregnancy is a critical global public health issue, with approximately 16 million adolescents aged 15 to 19 giving birth each year, accounting for 11% of all global births. This phenomenon significantly impacts maternal and child health, as well as the social and economic well-being of young mothers and their families. In Mexico, adolescent pregnancy rates remain among the highest globally, with more than 90% of new sexually transmitted infections (STIs) occurring in young women, and significant disparities in fertility rates between rural (2.8) and urban (2.01) areas.

Several studies have identified key risk factors associated with adolescent pregnancy, including lack of knowledge about contraception, low risk perception, peer pressure, low self-esteem, and limited communication about sexuality. Additionally, many traditional interventions have been limited in scope and effectiveness, as they fail to integrate motivational approaches or technological tools that align with adolescent communication preferences.

To address these challenges, the "Be Yourself" educational intervention was designed based on Self-Determination Theory and behavioral change models, aiming to foster self-determined motivation for adolescent pregnancy prevention. The intervention incorporates innovative strategies, including an artificial intelligence-powered chatbot and a web-based platform, allowing for dynamic, interactive, and accessible learning experiences for adolescents.

General Objective:

To evaluate the preliminary efficacy of the "Be Yourself" intervention in increasing self-determined motivation and promoting preventive behaviors against adolescent pregnancy among secondary school students.

Specific Objectives:

1. Assess the intervention's impact on adolescents' self-determined motivation.
2. Evaluate changes in knowledge regarding sexual and reproductive health.
3. Measure improvements in communication about sexuality with parents, friends, and partners.
4. Determine the acceptability and feasibility of using a chatbot for sexual health education.
5. Examine changes in behavioral intentions and pregnancy prevention behaviors. Study Design This study follows a pilot randomized controlled trial (RCT) with a pretest-posttest design, comparing the "Be Yourself" educational intervention to a traditional sexual education program.

Participants and Inclusion Criteria:

• Adolescents aged 12 to 15 enrolled in public secondary schools in Santa Catarina, Nuevo León, Mexico.
• Access to the internet to participate in the web-based platform.
• Parental consent and adolescent assent obtained.
• No prior participation in similar programs in the last six months.

Exclusion Criteria:

• Adolescents are diagnosed with psychological or cognitive disorders that interfere with comprehension.
• Current pregnancy.

Sample Size and Sampling Procedure:

The study will recruit 150 participants, randomly assigned in a 1:1 ratio to the following groups:

• Experimental Group (EG): Receives the "Be Yourself" intervention, including interactive sessions, chatbot support, and access to the web platform.
• Control Group (CG): Receives conventional sexual education through lecture-based sessions.

Participants will be randomly selected, accounting for a 20% dropout rate. Description of the "Be Yourself" Intervention The intervention consists of three interactive educational sessions, combining theoretical and practical strategies in an innovative digital environment.

Intervention Components:

1. AI-Powered Chatbot: Answers sexual health questions, provides reminders, and encourages participation.
2. Web-Based Platform: Offers multimedia resources, interactive activities, and discussion forums.
3. Educational Sessions: Based on the Self-Determination Model for Adolescent Pregnancy Prevention.

Session Structure:

• Session 1: Introduction to self-determined motivation and self-awareness.
• Session 2: Strategies for responsible decision-making and assertive communication.
• Session 3: Goal setting and pregnancy prevention planning. Variables and Measurements

Validated instruments with high reliability coefficients (Cronbach's alpha ranging from 0.77 to 0.95) will be used to evaluate:

1. Primary Variables:

   • Self-determined motivation for pregnancy prevention.
   • Change in sexual and reproductive health knowledge.

2. Secondary Variables:

   • Communication about sexuality with parents, friends, and partners.
   • Behavioral intention for pregnancy prevention.
   • Level of satisfaction and engagement with the intervention. Assessments will be conducted at three time points: pretest, posttest, and a 3-month follow-up.

Data Analysis

The SPSS v26.0 software will be used for statistical analysis:

1. Descriptive Analysis: Means, standard deviations, and frequencies.

2. Normality Test: Kolmogorov-Smirnov test to determine data distribution.

3. Pretest-Posttest Comparisons:

   • Paired t-test (parametric variables).
   • Mann-Whitney U test (non-parametric variables).

4. Repeated Measures ANOVA to analyze changes over time. A significance level of p < 0.05 will be considered. Ethical Considerations

   • The study has been approved by the Ethics Committee of the School of Nursing at the Universidad Autónoma de Nuevo León.
   • Parental consent and adolescent assent will be obtained.
   • Confidentiality will be ensured through anonymous participant ID codes.
   • Participation is voluntary, with the option to withdraw at any time without consequences.

Expected Outcomes

The "Be Yourself" intervention is expected to:

1. Increase adolescents' self-determined motivation.
2. Enhance knowledge of sexual health and pregnancy prevention.
3. Improve communication about sexuality with parents and peers.
4. Strengthen behavioral intentions regarding contraception and pregnancy planning.
5. Increase acceptance of digital strategies for health education.

Inclusion Criteria:

• Adolescents between 11 and 15 years of age enrolled in public high schools in Nuevo León will be included.

public high schools in Nuevo León.

• Be male or female, regardless of whether they have initiated their sexual life. sexually active.
• Have access to a computer room with internet to use the web page and the interventions chatbot.

the interventions chatbot.

• Live at the same address with their parents or legal guardian.

Exclusion Criteria:

• Have previously participated in a similar sexuality intervention.
• Have cognitive or developmental difficulties that impede their understanding of the intervention and use of the technology platform, including people with
• Autism Spectrum Disorder (ASD) at levels that affect functional communication, Attention Deficit Hyperactivity Disorder (ADHD) with severe attention difficulties, or those who cannot read and write.

Individual participant data (IPD) will not be shared due to strict ethical and confidentiality considerations. The study complies with current personal data protection regulations, guaranteeing the privacy and security of the information of the adolescent participants. The results will be presented only in aggregated and anonymized form, avoiding any possibility of identification. In addition, the informed consent signed by the participants and their legal guardians does not contemplate the disclosure of individual data to third parties.