Scientists in Israel have linked prolonged stress during outbreaks of Israeli-Palestinian conflict with lowered sperm quality in Israeli men.
Sperm collected from Israeli men during periods of military hostility had lower motility compared with those from samples taken during times of lower hostility. The study presented at the International Summit on Assisted Reproduction and Genetics in Tel Aviv, found sperm moved more slowly in 37 percent of sperm samples taken during, and shortly after, two periods of conflict between Israel and Gaza.
'Mental stress is known to have an adverse effect on fertility, but there is little research on the impact of stress on sperm quality,' said Dr Eliahu Levitas of Ben-Gurion University Faculty of Health Sciences and director of the IVF Unit and sperm bank at Soroka University Medical Centre, Israel, who led the research. 'This study shows that prolonged stress can have an effect on sperm quality.'
Researchers found the probability of weak motility was 47 percent higher in sperm samples taken during periods of prolonged stress. Sperm motility refers to the movement and swimming of sperm. Weak motility makes it less likely that the sperm will successfully fertilise an egg.
Researchers analysed 10,536 samples donated during quiet periods between 2009 and 2017, which were compared to 659 sperm samples taken during and up to two months after two military conflicts between Israel and Gaza in 2012 and 2014. The subjects' average age was 32, and 44 percent were smokers.
Dr Levitas explained: 'Our reasoning was that even men who heard incoming rocket warning sirens during a conflict experienced stress throughout the day over a longer period. We were surprised to discover that there is a connection between the security situation and the sperm counts.'