WeChat-Delivered Mobile Medical Nutrition Therapy Intervention in Gestational Diabetes Mellitus: Randomized Controlled Trial.

Background: Medical nutrition therapy (MNT) serves as the foundational intervention in the clinical management of gestational diabetes mellitus (GDM) management. However, inadequate supportive care often hinders patients' ability to sustain dietary modifications and self-management behaviors, particularly for complex regimens. Flexible online interventions are thus gaining interest as adjuncts to clinical care, with the potential to improve the outcomes of GDM self-management. Objective: This study sought to evaluate the benefits of WeChat-delivered medical nutrition therapy (WeMNT), a WeChat-delivered MNT intervention, for patients with GDM. Methods: A parallel-group, single-blind randomized controlled trial (with outcome assessor blinding) was implemented at a university hospital's obstetric clinic. Eligible participants were those with a 24- to 28-week singleton pregnancy, a GDM diagnosis confirmed by the 75 g oral glucose tolerance test, no requirement for insulin therapy, and the ability to use a smartphone and WeChat, as well as to communicate in Chinese. Participants were randomized 1:1 to the intervention (n=47, 50%) or control group (n=47, 50%) using a random number table. The WeMNT intervention was designed per the behavior change wheel framework: (1) analyze capability-, opportunity-, and motivation-based barriers related to MNT adherence; (2) formulate targeted intervention functions; and (3) select evidence-based behavior change techniques. Three WeChat mini-programs served as the core delivery platform to implement the multifaceted intervention functions. The primary outcomes measured in this study included fasting blood glucose, 2-hour postprandial glucose (2hPG), hemoglobin A1c (HbA1c), and gestational weight gain (GWG). The secondary outcomes assessed included obstetric complications and neonatal parameters. Intention-to-treat analysis using adjusted generalized linear mixed models was conducted to evaluate the effects of the intervention. Results: From March 2023 to October 2023, a total of 94 participants were enrolled in this study. Among the participants, 88 (93.62%) individuals (mean age 32.18, SD 5.04 years) successfully completed the study, 44 (46.81%) in the intervention group and 44 (46.81%) in the control group. Approximately 68.18% (30/44) of the participants in the intervention group demonstrated sustained adherence, as expected, adhered to the diet plan ≥60% of the days. Compared with the control group, the intervention group showed a significantly greater decrease in GWG over time (group×time interaction: β=-1.96, 95% CI -3.58 to -0.34; P=.02), with no significant effects on fasting blood glucose. Conversely, significant decreases in 2hPG (β=-0.12, 95% CI -0.19 to -0.04; P<.001) and HbA1c (β=-0.49, 95% CI -0.74 to -0.23; P<.001) were noted in the intervention group. No unexpected maternal adverse events occurred, and no significant effects on other health outcomes were detected. Conclusions: As a WeChat-delivered, behavior change wheel-informed intervention, WeMNT successfully reduced 2hPG, HbA1c, and GWG in GDM management. Its integrated self-management model yields robust evidence, validating this patient-centered tool as a viable option for clinical adoption.