Depression is the most common psychological disorder during the perinatal period, and its negative effects extend to mothers, babies, their family and society. Scientific evidence points to the urgency of designing preventive interventions and concludes that the gestational period is the most appropriate time to implement these interventions. However, many pregnant women do not seek professional help due to a lack of knowledge about the importance of mental health, its impact, and the available intervention options, as well as a lack of time and financial resources. E-health interventions can be an efficient, cost-effective, and accessible resource for preventing postpartum depression that can circumvent the barriers that pregnant women face. This randomized clinical trial will examine the efficacy of Healthy Moms and Babies, an app aimed at preventing postpartum depressive symptomatology. The second objective of this study is to analyze the effectiveness of the tool in preventing anxious symptomatology. The primary outcome measure is the difference in the mean score between the intervention and control groups on the Patient Health Questionnaire-9 (PHQ-9) at the end of the intervention and at 3 and 6 months postpartum. The secondary outcome will be determined by using the Generalized Anxiety Disorder Screener (GAD-7) at the same time points. The research findings can be used to determine pregnant women’s use of the e-health application for the prevention of postpartum depression, whether the Healthy Moms and Babies intervention app is an effective and useful resource, and what modifications will need to be made to the tool in future updates.