Exploring the Relationship Between Mobile Apps and Pregnancy Health Literacy: A Probabilistic Network approach (Preprint)

BACKGROUND Health literacy is crucial for pregnancy outcomes, yet 15-44% of pregnant women have low health literacy, negatively affecting maternal and fetal health. While pregnancy apps are increasingly used to support health literacy, the psychological mechanisms through which they influence behavior remain unclear. Understanding these mechanisms is essential for designing effective interventions. Cognitive Load Theory (CLT) and the Integrated Model of Cognitive-Affective Learning with Media (ICALM), which treats emotional and cognitive processing as equally important, provide theoretical frameworks for understanding these digital interventions in pregnancy's emotionally intense context. OBJECTIVE This study aims to understand the psychological and social-cognitive pathways through which engagement with pregnancy apps may enhance health literacy during pregnancy. METHODS This cross-sectional survey study included 998 pregnant and early postpartum women aged 18-45 years from the United States. For comparative analyses, participants were stratified into Pregnancy+ users (n=362), other pregnancy app users (n=507), and non-app users (n=129). We measured digital engagement, emotions, health literacy levels, support levels and sources, and health behaviors including physical activity, nutrition, and stress management. A Bayesian network (BN) model was constructed and validated by incorporating domain knowledge from CLT, ICALM and pregnancy literature. The BN underwent systematic refinement through bootstrap resampling (n=1000) to evaluate arc strength, followed by k-fold cross-validation (k=5) to assess model generalizability and predictive performance. RESULTS The final BN revealed that digital engagement may influence health outcomes through two indirect pathways rather than direct effects. First, digital engagement was associated with support source utilization, which subsequently linked to health literacy. Second, digital engagement was related to emotions, which then affected health literacy and – to a lesser extent – health behaviors physical activity, nutrition, and stress management. No direct pathways from digital engagement to health literacy or behaviors were retained. Pregnancy+ users demonstrated stronger adherence to these psychological pathways compared to other app users and non-users, by demonstrating more joyfulness (5.1 vs 4.7, p = .046), elevated support levels (4.1 vs 3.9, p =.031), and higher critical health literacy scores (8.4 vs 8.2 vs 7.7, p <.001). Pregnancy+ users also showed higher engagement frequencies (p < .000) and more frequently cited pregnancy apps as valuable information sources (78% vs 68%, p = .012) compared to users of other pregnancy apps. CONCLUSIONS This study identified specific psychological and social-cognitive pathways through which digital interventions may influence pregnancy health literacy. Specifically, pregnancy apps may enhance health literacy by fostering positive emotions and feelings of support. In line with CLT and ICALM, this suggests that emotionally supportive pregnancy apps may reduce irrelevant emotional processing that typically uses cognitive capacity and enhance information retention. This study validates CLT and ICALM within pregnancy contexts and demonstrates BNs' promise for revealing complex psychological relationships, thereby better supporting maternal health in the digital age.