Encouraging men to have more frequent ejaculations may boost their fertility, according to researchers who found that sperm deteriorates over time as it remains in the body.<\/p>\n
The longer men went without sex, the more their sperm showed signs of DNA damage and oxidative stress, and the more tests rated the sperm as less viable and poorer swimmers.<\/p>\n
The work has implications for fertility clinics and suggests that if doctors want to collect the best quality sperm, men should probably not abstain from ejaculating for several days as guidelines suggest.<\/p>\n
\u201cIn men, the negative effects we found on sperm DNA damage and oxidative damage were large-ish, so we are confident that this is a biologically meaningful and important effect,\u201d said Dr Krish Sanghvi, a biologist at the University of Oxford and lead author on the study.<\/p>\n
The findings emerged from a meta-analysis that combined 115 human studies involving nearly 55,000 men, and 56 studies that looked at the impact of sperm storage in 30 non-human species. In humans and other animals, sperm tended to deteriorate while it was stored in males, regardless of the male\u2019s age.<\/p>\n
The World Health<\/a> Organization (WHO) recommends men abstain from ejaculating for two to seven days before giving sperm for fertility tests or IVF. But the guidelines were designed to obtain the highest sperm count rather than prioritising the best quality sperm.<\/p>\n That decision may now become more nuanced. \u201cAll we recommend is that clinicians and couples reconsider whether long abstinence is always good, because abstinence leads to deterioration in sperm quality,\u201d Sanghvi said. Details are published in Proceedings of the Royal Society B<\/a>.<\/p>\n \u201cIf sperm quantity is the only thing that matters for a clinic or couple, then sexual abstinence is not necessarily a bad thing,\u201d Sanghvi said. \u201cBut usually fertilisation success will be determined not only by how many sperm there are but the quality of the sperm too, for example in IVF<\/a>.\u201d<\/p>\n