This randomized controlled trial aims to evaluate the effect of a mobile application-based support and counseling program on women in the preconception period. The study includes women aged 18 to 49 who plan to conceive within two years and meet the eligibility criteria. Participants are randomly assigned to an intervention group receiving structured preconception counseling through a mobile application or a control group receiving standard information via a booklet. The intervention consists of weekly educational modules delivered over four weeks, followed by follow-up assessments at 4 and 12 weeks. Primary outcomes include changes in preconception knowledge, attitudes, and self-efficacy. The study seeks to determine whether mobile health-based counseling enhances preconception preparedness compared with standard information.

This randomized controlled trial investigates the effectiveness of a structured mobile application-based support and counseling program designed for women in the preconception period. Preconception care plays a critical role in improving maternal and fetal outcomes by addressing biomedical, behavioral, and psychosocial risk factors before pregnancy. Despite increasing global use of mobile health technologies, there is no comprehensive mobile application-based preconception counseling program developed and evaluated in Türkiye. This study aims to address this gap by implementing a digitally delivered intervention grounded in established guidelines from the CDC and WHO.

The study includes women aged 18 to 49 who are in the preconception period, have never been pregnant, plan to conceive within two years, can use a smartphone, and have internet access. Women who are currently pregnant, health professionals, those with diagnosed psychiatric conditions, or those who have previously received preconception counseling are excluded. A total of 110 eligible participants are enrolled and randomly assigned to intervention or control groups using a simple randomization procedure generated through an online randomization system (random.org). Because the intervention requires participant engagement with content, the study is conducted as a single-blind design, with participants unaware of their group allocation.

The intervention group receives a four-week mobile application-based counseling program developed using the ADDIE (Analysis, Design, Development, Implementation, Evaluation) instructional design model. The application delivers weekly modules covering preconception care concepts, risk assessment, nutrition, supplementation, physical activity, immunization, sexually transmitted infections, environmental exposures, oral and dental health, psychosocial well-being, reproductive planning, and lifestyle behaviors such as tobacco, alcohol, and medication use. Each module includes structured educational content, reminders, and communication tools enabling researcher-participant interaction. Participants receive weekly follow-ups via messaging to identify difficulties, support adherence, and address questions. The application also includes built-in progress tracking and notification functions.

The control group receives a printed booklet containing standardized preconception information aligned with the topics covered in the intervention modules. Control group participants do not receive digital follow-up but participate in the same assessment schedule as the intervention group.

Data are collected at baseline, at week 4, and at week 12 after the start of the study. Instruments include: a descriptive information form, the Preconception Knowledge and Attitudes Scale, the General Self-Efficacy Scale, a preconception risk assessment form, and for the intervention group, the Mobile Application Usability Scale. Baseline assessments include sociodemographic characteristics, lifestyle indicators, and preconception risk factors. Week 4 assessments measure short-term changes in knowledge, attitudes, and self-efficacy. Week 12 assessments evaluate persistence of intervention effects and longer-term retention of gains.

The primary outcomes are changes in preconception knowledge, attitudes, and self-efficacy. Secondary outcomes include user-reported usability and acceptability of the mobile application. The study evaluates whether a mobile health-based digital counseling approach provides measurable benefits beyond conventional booklet-based information and whether its effects persist beyond the immediate intervention period.

The findings are expected to contribute to the development of evidence-based, scalable, digital preconception care strategies appropriate for primary health care settings, particularly in contexts where accessibility, continuity, and standardization of preconception counseling services are limited.

Inclusion Criteria:

1. Women aged 18 to 49 years.
2. In the preconception period and planning to conceive within the next two years.
3. Never been pregnant.
4. Able to read and understand Turkish.
5. Having a smartphone and internet access.
6. Willing to participate and provide informed consent.

Exclusion Criteria:

1. Currently pregnant.
2. Having a diagnosed psychiatric disorder that may interfere with participation.
3. Previous participation in structured preconception counseling or training.
4. Being a health professional or a student in a health-related field.
5. Inability to use a mobile application due to cognitive, visual, or physical limitations.
6. Participation in another ongoing research study.

Only individuals who self-identify as women are eligible to participate.

Participants are blinded to group assignment; the researcher delivering the intervention is not blinded.