Associations Between Perceived Stress and Sperm DNA Methylation Among Men Attending a Fertility Center

BACKGROUND: Stress has been negatively associated with reproductive outcomes, including poor semen quality in men; however, the molecular mechanisms underlying these associations remain poorly understood. OBJECTIVES: This study aimed to evaluate the association between perceived stress and sperm DNA methylation patterns in men undergoing infertility treatment. MATERIALS AND METHODS: The study was conducted on 169 men attending the Massachusetts General Hospital Fertility Clinic who provided a semen sample and completed the short version of the Cohen Perceived Stress Scale (PSS-4) to quantify perceived psychological stress. Sperm DNA methylation was measured using the Illumina EPIC Array (v1). Associations between stress and DNA methylation were investigated using a linear regression model (CpGassoc) and eXtreme Gradient Boosting (XGBoost), a decision tree-based machine learning approach. The biological relevance of the identified regions was assessed using Metascape. RESULTS: Median (IQR) level of perceived stress reported by the Environment and Reproductive Health (EARTH) Study participants was 4 (3, 6) on the 14-point PSS scale. Perceived stress was associated with 811 differentially methylated CpGs (DMCs; p < 0.001) in the regression model and 782 CpGs predictive of perceived stress identified by XGBoost. Stress-associated genes were enriched in pathways related to cell morphogenesis, behavior, and neurodevelopment. CONCLUSION: Despite not achieving statistical significance after correction for multiple comparisons, our findings nevertheless provide novel insights into reduced fertility potential among men with high levels of perceived stress and highlight DNA methylation as a potential mechanism underlying of paternal epigenetic inheritance of stress-related phenotypes.