Abstract
BACKGROUND: Pregnancy is a period of significant psychological, physiological, and social change, which can increase vulnerability to emotional distress. While many interventions focus on detecting and treating symptoms of anxiety and depression during pregnancy, fewer target the promotion of wellbeing. The BienGestar study aims to evaluate the effectiveness of a digital, biopsychosocial, cognitive-behavioural intervention designed to promote mental health, wellbeing, and physical health during pregnancy and the postpartum period in a community-based sample of healthy pregnant women. METHODS: The study is a randomized controlled trial with two parallel arms: an intervention group and a control group. Participants will be recruited through public health centers in Catalonia, Spain. Eligible participants are pregnant women less than 15 weeks of gestation, aged 18 or older, with access to an internet-connected device and able to understand and read Spanish. After providing informed consent and completing baseline assessments, participants will be randomized into one of the two groups. The intervention consists of a 20-week structured program delivered through a secure online platform, with daily activities and psychoeducational content adapted to the gestational stage. Outcomes will be assessed at baseline (gestational week 15), post-intervention (gestational week 36), and postpartum (45 days after delivery). Primary outcomes include mental wellbeing, life satisfaction, and symptoms of anxiety and depression. Secondary outcomes include prenatal attachment, self-efficacy, birth experience, and infant health indicators. Obstetrical and neonatal data will be collected from medical records. All analyses will follow the intention-to-treat principle, and a per-protocol analysis will also be conducted to assess the intervention's efficacy among participants who adhered to the program. DISCUSSION: This study introduces a novel, health-promotion-focused approach to perinatal mental health care. By targeting psychological wellbeing rather than emotional distress, and by offering a fully online, self-guided intervention integrated into primary care, BienGestar may contribute to scalable, preventive strategies to support women throughout pregnancy. If effective, the intervention could be implemented broadly as part of routine prenatal care to enhance maternal wellbeing and infant outcomes. TRIAL REGISTRATION: ClinicalTrials.gov: NCT06871397. Prospectively registered on March 11, 2025.