Impacto de uma intervenção baseada em mindfulness em biomarcadores do estresse e sintomas psicológicos em mulheres com perda gestacional de repetição: um ensaio clínico randomizado

Abstract

Introduction: Women with recurrent pregnancy loss (RPL) often exhibit high levels of depression, anxiety, and stress, which negatively impact their quality of life. In this context, mindfulness-based therapy has been proposed as a strategy to promote emotional well-being and improve the quality of life of these women. Objective: The primary objective of this study was to evaluate the impact of a Mindfulness-Based Intervention (MBI) on salivary stress biomarkers (cortisol, alpha-amylase, and IgA) in women with RPL. In addition, symptoms of depression, stress, and anxiety, as well as overall psychological well-being, were assessed using the Depression, Anxiety and Stress Scale-21 (DASS-21) and the Psychological General Well-Being Index (PGWB-I), before and after the intervention. Methods: This randomized clinical trial was conducted with 35 women with a history of two or more pregnancy losses, recruited from the RPL Outpatient Clinic of the Hospital das Clínicas, Federal University of Minas Gerais (HC-UFMG). Participants were randomized by computer software into two groups: intervention (MBI) and control. The intervention was delivered online and lasted eight weeks. All participants were assessed at baseline and after eight weeks through salivary biomarker collection, as well as using the DASS-21 and PGWB-I questionnaires. Statistical analysis involved testing the normality of continuous variables to guide the use of parametric methods (means, standard deviations, t test) or nonparametric methods (medians, quartiles, Mann-Whitney test). Categorical variables were analyzed using chi-square or Fisher’s exact test. Associations between variables were assessed using Spearman´s rank correlation coefficient. Results: No significant time × group interaction was detected for salivary stress biomarkers, including cortisol (p = 0.672), amylase (p = 0.342) and IgA (p = 0.148). However, a significant time × group interaction was observed for the total DASS-21 score (p = 0.018), as well as for the depression (p = 0.026) and stress (p = 0.015) subscales, indicating that participants in the intervention group experienced greater reductions in psychological distress compared with the control group over time. Regarding psychological well-being, robust interactions were found for the total PGWB-I score (p < 0.001) and for multiple domains, including anxiety (p = 0.008), depression (p = 0.007), positive well-being (p = 0.001), self-control (p = 0.007), perceived health (p = 0.013), and vitality (p < 0.001), reflecting a broad beneficial impact of the intervention on mental health. IBM was more effective in those with greater initial distress (r = -0.641; p = 0.006) and in younger women (r = 0.593; p = 0.012). The number of previous miscarriages did not influence the magnitude of the response to the intervention (r = 0.137; p = 0.600). Conclusion: An MBI improved self-reported psychosocial outcomes in women with RPL, with no evidence of effect on salivary stress biomarkers over eight weeks. These findings support the clinical value of MBI for well-being and suggest that biological changes, if present, may require larger samples, more sensitive measures, or longer follow-up to be detected.