More frequent ejaculations may boost men’s fertility, research suggests | Fertility problems

Encouraging men to have more frequent ejaculations could increase their fertility, according to researchers who found that sperm deteriorate over time the longer they remain in the body.

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 less free-swimming.

This work has implications for fertility clinics and suggests that if doctors want to collect the highest quality sperm, men probably should not refrain from ejaculating for several days, as guidelines suggest.

“In men, the negative effects we saw on sperm DNA damage and oxidative damage were significant, so we are confident that this is a biologically significant and important effect,” said Dr. Krish Sanghvi, a biologist at the University of Oxford and lead author of the study.

The results come from a meta-analysis combining 115 human studies involving nearly 55,000 men and 56 studies examining the impact of sperm storage in 30 non-human species. In humans and other animals, sperm tended to deteriorate when stored in males, regardless of their age.

The World Health Organization (WHO) recommends that men abstain from ejaculation for two to seven days before donating sperm for fertility tests or IVF. But the guidelines were designed to get the highest sperm count rather than prioritizing the best quality sperm.

This decision could now become more nuanced. “All we recommend is that clinicians and couples reconsider whether prolonged abstinence is always a good thing, because abstinence leads to deterioration in sperm quality,” Sanghvi said. Details are published in the Proceedings of the Royal Society B.

“If sperm quantity is the only thing that matters to a clinic or a couple, then sexual abstinence is not necessarily a bad thing,” Sanghvi said. “But generally, the success of fertilization will be determined not only by the number of sperm, but also by their quality, for example in IVF.”

Although the Oxford study found no impact of abstinence on male fertilization rates, a recent clinical trial involving 453 couples found a link.

In the trial, IVF doctors compared the pregnancy rates of two groups of couples. Men in the first group refrained from ejaculating for less than two days before providing sperm for IVF treatment. Men in the second group followed WHO recommendations and abstained for two to seven days before providing sperm. The pregnancy rate was 46% when men abstained for less than 48 hours, and only 36% among those who abstained longer.

For couples trying to conceive naturally, a time frame of between two and seven days might make sense. Abstain for too long and the sperm may become damaged and have poor motility. If you abstain too little, the sperm may not be numerous or mature enough. “For couples, our recommendation would be that longer abstinence is not always a good thing and that a balance between quantity and [and] quality must be achieved,” Sanghvi said.

Allan Pacey, professor of andrology at the University of Manchester, said: “There has been growing evidence in recent years that a shorter period of abstinence could be beneficial during assisted reproduction such as IVF. Indeed, with a short period of abstinence, sperm are fresher, more mobile and have lower levels of DNA damage.”

“The two to seven day abstinence rule is important to follow for men undergoing semen analysis at the diagnostic stage, as it allows results to be compared over time between laboratories and against international benchmarks. But it is not as important when IVF treatment actually takes place.

“For assisted reproductive technology (ART) treatments, it is probably more important to have the freshest, healthiest sperm. We can do IVF treatment with low sperm counts, and even higher if we do ICSI (intracytoplasmic sperm injection), so it is not as necessary for men to preserve their sperm as we once thought.”