In a study of 50 men attending an infertility clinic, researchers found that those who expressed their emotions by talking about problems and telling colleagues and loved ones when they were upset or frustrated had higher sperm counts than those who did not.
The preliminary findings open the way for men with below-average sperm counts, or zero sperm unconnected to genetic or chromosomal defects, to improve their fertility by altering the way they cope with stressful events.
"Men who are on death row for long periods completely stop making sperm. The implication is that because they are under high levels of stress, it has, in this extreme case, led to a complete breakdown of reproductive potential," said Keith Hurst, who conducted the research with a fellow psychologist at Leeds University, Dr Louise Dye, and a consultant obstetrician and gynaecologist from the Halifax General Hospital, Martin DeBono.
One explanation for the potential link between fertility and stress is that the increased levels of hormones produced under stress could inhibit the production of some other hormones needed to produce healthy sperm.
The men studied were divided into those who had subnormal sperm counts and those who had normal levels. They all completed questionnaires on how they much they wanted a child, how much stress they had in their lives and their socio-economic background. There were no significant differences between the groups.
The men then kept a diary on any potentially stressful situations they had encountered and how they had dealt with them.
Although the men who had normal sperm counts experienced more stressful events, the way they coped with them was very different. An analysis of their behaviour showed that they used a cathartic coping mechanism, such as confiding in a colleague, 21 per cent more often than the other men. Mr Hurst said: "Possibly the additional use of cathartic coping in the fertile men has reduced their potential stress levels ... An increased use of this particular method of coping may be beneficial to sub-fertile men."