Psychological mechanisms of prenatal mindfulness training on antenatal blood pressure reduction: A pilot study.

BACKGROUND: Hypertensive disorders of pregnancy (HDP) are a significant cause of perinatal morbidity and mortality. Mindfulness training (MT) shows promise for reducing blood pressure during pregnancy; however, the underlying mechanisms by which MT exerts this effect remain unclear. OBJECTIVES: The objectives of this pilot randomized clinical trial were to study psychological mechanisms through which MT may reduce blood pressure in pregnancy. STUDY DESIGN: Pregnant participants were randomized to an 8-week phone-delivered mindfulness intervention or usual care. Antenatal blood pressure values were extracted from medical records before and after the intervention to examine change in blood pressure. Participants also completed self-report measures of depression, anxiety, perceived stress, and mindfulness before and after the intervention. RESULTS: Twenty-nine participants were randomized to phone-based MT (N = 15) or usual care (N = 14). Blood pressure significantly decreased across participation among those randomized to MT vs. usual care (systolic blood pressure (F = 5.093, p = .035); diastolic blood pressure (F = 9.689, p = .005)). Reductions in perceived stress mediated the relationship between mindfulness training and decreases in systolic-but not diastolic-maternal blood pressure. CONCLUSIONS: Findings from this pilot trial suggest that reductions in perceived stress may underlie the effect of prenatal mindfulness training on lowering maternal systolic blood pressure. CLINICAL TRIAL REGISTRATION: The ClinicalTrials.gov identifier is NCT03679117.