The Mindfulness-Based Stress Reduction program (MBSR) is a structured intervention that blends meditation, formal and informal practices and yoga to enhance attention and emotional regulation and overall well-being. Its potential benefits are particularly significant for couples dealing with infertility and awaiting assisted reproductive technology (ART) treatment, a condition often accompanied by high perceived levels of stress, anxiety, and depression. This pilot study on six participants, consisting of three infertile couples, aims to introduce an objective measure of trainer-trainee connection by applying Cross Recurrence Quantification Analysis (CRQA) to systolic-to-systolic time interval data of each dyad trainee-trainer. The trainer-trainee relationship is fundamental in MBSR, creating a supportive, trust-based environment that enables participants to fully engage in the practices, overcome challenges, and experience transformative benefits. Three CRQA features (determinism, recurrence rate, and longest diagonal length) were extracted from two phases (resting state and meditation task) of both the first and final MBSR sessions. Results revealed a significant increase in cardiovascular synchrony during the final session, particularly between meditation and resting states across all the three CRQA features (p-value < 0.05). No significant differences were observed in the first session between rest and meditation. While these findings are preliminary, this approach shows promise as an objective tool for assessing the strength of the trainer-trainee relationship and the effectiveness of group interventions.