Oral tobacco (snus) use and sperm quality in men attending fertility treatment: a cross-sectional study

Abstract Background Snus, a moist oral tobacco product, is widely used in Norway and Sweden, but its association with semen quality is uncertain. This study aimed to determine if the use of oral tobacco (snus) is associated with sperm quality in men undergoing fertility treatment. Methods This was a single-center cross-sectional study using data from 1805 men with a mean age of 34.5 years who were undergoing their first fertility treatment at St. Olavs Hospital in Norway from January 2017 to March 2022. Using linear and logistic regression, we compared sperm parameters between men with and without snus use, adjusting for age, body mass index, and smoking status. Results Of the 1583 men with known snus status, 461 used snus. Snus users had lower sperm concentration (-12.1%, 95% CI -19.5 to -8.1), lower total progressive motile sperm count (-20.5%, 95% CI -25.9 to -15.3), and lower total sperm count (-16.2%, 95% CI -25.6 to -12.0) than those who did not use snus. Furthermore, snus users had higher odds of having a total sperm count below the World Health Organization cutoff of 39 x 10⁶/sample (odds ratio 1.26, 95% confidence interval 1.01–1.60). The results were consistent in sensitivity analyses. Conclusions Men undergoing fertility treatment who used snus had lower sperm concentration, total number of progressive motile sperm cells, and total sperm count, but similar semen volume and progressive motility percentage compared to men who did not use snus. These findings highlight the importance of considering snus use as a potential risk factor in male fertility assessment.