Abstract

Introduction: The prevalence of unexplained infertility is 15% among all infertility cases and mental

distress has been suggested as a cause of it. Emotional stress can cause some abnormalities in semen

parameters, although the basic biochemical principles of the relationship between mental stress and semen

parameters are poorly understood. Recently there is emerging interest in reactive oxygen species (ROS) with

respect of their unfavorable effect on fertility as a result of lipid peroxidation. In this study, the effects of

mental stress on the Malondialdehyde (MDA) levels, an indirect indicator of lipid peroxidation and semen

parameters were investigated.

Materials and Methods: Semen samples were collected from 36 healthy volunteer students of the fourth

semester of the medical school just before (stress period) and 3 months after (non-stress period) the final

examinations by masturbation. Psychological stress of the participants was measured with the State Trait

Anxiety Inventory. After standard semen analysis, MDA activity was measured in the seminal plasma. The

data of the stress and non-stress periods were compared via paired samples t test. Correlation analysis

between MDA levels and sperm parameters was made for both stress and non-stress periods. A value of p less

than 0.05 was considered statistically significant. Correlations between MDA levels and sperm parameters also

were examined by Pearson Correlation test. A value of p less than 0.05 was considered statistically significant.

Results: During the stress period, stress scores were higher compared with the non-stress period

(43.61±10.71 vs. 37.67±9.61). Our data showed that, sperm count, percentage of progressive motility and

percentage of normal morphology significantly decreased during the stress period. Seminal plasma MDA

levels were significantly higher during the stress period compared with the non-stress period (50.19±48.22 vs.

16.19±22.59 nmol/109 spermatazoa). There was a positive correlation between seminal plasma MDA levels and

percentage immobility at ½ and 2nd hours at the stress period. And seminal plasma MDA level was found to

correlate negatively with the percentage normal morphology and total sperm count.

Conclusion: Our results indicate that mental stress can cause an unfavorable effect on semen parameters.

Increased seminal plasma MDA levels at stress period may be a result of overproduction of ROS in semen. We

would suggest that stress may cause oxidative stress in semen and in this way it could be responsible for male

subfertility. We think that this subject deserves further studies.