Mindfulness-Based Stress Reduction as an Adjunct Therapy for Gestational Diabetes Mellitus: A Randomized Controlled Trial Protocol

Background: Gestational diabetes mellitus (GDM) is a common pregnancy complication associated with substantial maternal and fetal health risks. Apart from metabolic disturbances, a confirmed GDM diagnosis often elicits anxiety, depression, and diabetes-specific distress, which may activate the hypothalamic-pituitary-adrenal (HPA) axis, exacerbate insulin resistance, and undermine glycemic regulation, creating a psychometabolic vicious cycle. Mindfulness-Based Stress Reduction (MBSR) is an evidence-based intervention that facilitates emotional regulation and boosts stress resilience. Despite its proven benefits in type 2 diabetes, its efficacy on glycemic control and psychological well-being in GDM remains inadequately examined in rigorous trials. Methods and Analysis: In this prospective, assessor-blinded, randomized controlled trial, 300 pregnant women with GDM (24-28 weeks) will be randomly assigned (1:1) to an 8-week group-based MBSR program plus routine standard antenatal care (intervention group) or standard care plus matched gestational health education (control group). The trial will be conducted at Fujian Maternity and Child Health Hospital, Fuzhou, China. The health education covers general pregnancy health knowledge but without incorporating mindfulness or stress-management strategies, serving as an attention control. The primary outcome is the change in glycated hemoglobin (HbA1c) from baseline to the post-intervention at 36-37 gestational weeks. Secondary outcomes include continuous glucose monitoring metrics (Time in Range, Coefficient of Variation), psychological indicators (anxiety, depression, mindfulness, diabetes distress), self-management adherences, insulin usage rate, and maternal and neonatal clinical outcomes. The primary outcome will be analyzed using intention-to-treat linear mixed-effects models, with secondary outcomes analyzed via generalized estimating equations or chi-square tests as applicable. The trial will include 300 participants (150 per group), ensuring no less than 90% statistical power to detect a between-group difference of 0.35% in HbA1c variation. Additional per-protocol analysis and exploratory mediation analyses will also be conducted. Conclusion: This trial protocol presents a randomized controlled trial aiming to generate high-quality clinical evidence regarding the efficacy of MBSR in improving psychological status and optimizing glycemic regulation in GDM. The findings, once available, may facilitate its integration as a feasible adjunctive intervention within holistic GDM care.