The effect of mindfulness-based stress reduction training on fear of childbirth and psychological well-being in women experiencing premenstrual syndrome: a randomized controlled trial

Aim This study aimed to evaluate the effects of a Mindfulness-Based Stress Reduction (MBSR) program on premenstrual symptom severity, pre-pregnancy fear of childbirth, and psychological well-being in women experiencing Premenstrual Syndrome (PMS). Materials and methods This randomized controlled trial was conducted with 126 women experiencing PMS between June 2023 and November 2025 (MBSR group: n = 63; control group: n = 63). The intervention group participated in an 8-session online MBSR program, delivered twice weekly (40 min per session), while the control group received no intervention. Data were collected using the Premenstrual Syndrome Scale (PMSS), the Childbirth Fear - Prior to Pregnancy Scale (CF-PPS), and the Psychological Well-being Scale (PWBS). Between-group differences were analyzed using analysis of covariance (ANCOVA) adjusting for baseline values, and effect sizes were reported using partial eta-squared (η²). The trial was retrospectively registered (ClinicalTrials.gov, NCT06942169). Results The MBSR intervention was associated with statistically significant improvements in all outcomes compared to the control group. Adjusted analyses indicated a significant reduction in premenstrual symptom severity ( p < 0.001, η²=0.117) and fear of childbirth ( p < 0.001, η²=0.125), as well as a significant increase in psychological well-being ( p < 0.001, η²=0.285). These findings correspond to moderate effect sizes for PMSS and CF-PPS and a relatively large effect size for PWBS. Conclusion The findings suggest that MBSR may be an effective non-pharmacological intervention for reducing premenstrual symptoms, decreasing pre-pregnancy fear of childbirth, and improving psychological well-being in women experiencing PMS. However, the results should be interpreted with caution due to the short-term nature of the assessment and the absence of long-term follow-up data.