New research has shown that frequent ejaculation may improve male fertility by enhancing sperm quality, as sperm stored in the body for longer periods tends to deteriorate.
The study found that prolonged abstinence was linked to increased DNA damage and oxidative stress in sperm, reducing their viability and ability to swim effectively.
Researchers said the findings challenge existing medical guidance and could influence how fertility clinics approach sperm collection, suggesting that shorter abstinence periods may produce better-quality sperm than current recommendations.
“In 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,” said Dr Krish Sanghvi, a biologist at the University of Oxford and lead author on the study.
The conclusions were drawn from a large meta-analysis of 115 human studies involving nearly 55,000 men, alongside 56 studies on 30 non-human species. Across both humans and animals, sperm quality declined the longer it was stored in the male body, regardless of age.
The World Health Organization (WHO) currently advises men to abstain from ejaculation for two to seven days before fertility tests or IVF procedures. However, researchers noted that these guidelines prioritise sperm count rather than sperm quality.
That approach may now require reconsideration. “All we recommend is that clinicians and couples reconsider whether long abstinence is always good, because abstinence leads to deterioration in sperm quality,” Sanghvi said. Details are published in Proceedings of the Royal Society B.
“If sperm quantity is the only thing that matters for a clinic or couple, then sexual abstinence is not necessarily a bad thing,” Sanghvi said. “But 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.”
While the Oxford study did not find a direct link between abstinence and fertilisation rates in humans, evidence from a recent clinical trial suggests otherwise.
In the trial involving 453 couples, IVF doctors compared outcomes between two groups. Men who abstained for less than 48 hours recorded a pregnancy rate of 46%, compared to 36% among those who followed the WHO’s two- to seven-day guideline.
For couples trying to conceive naturally, researchers advised a balanced approach. Excessive abstinence may result in damaged and less motile sperm, while very short intervals may not allow enough time for sperm to mature.
“For couples, our recommendation would be that longer abstinence is not always a good thing, and that a balance between quantity [and] quality needs to be struck,” Sanghvi said.
Allan Pacey, a professor of andrology at the University of Manchester, said: “There has been growing evidence in recent years that a shorter abstinence time might be beneficial when undergoing assisted reproduction such as IVF. This is because with a short abstinence time the sperm are fresher, more motile and have lower levels of DNA damage.”
“The two to seven days abstinence rule is important to stick to for men undergoing semen analysis at the diagnosis stage, as it allows results to be compared over time between laboratories and against international benchmarks. But it isn’t as important when IVF treatment is actually taking place.”
“For assisted reproductive technology (Art) treatments, it’s having the freshest, most healthy sperm that is probably more important. We can do IVF treatment with a low number of sperm, and even lower if we do ICSI (intracytoplasmic sperm injection), so it isn’t as necessary for men to save up their sperm in the way that we once thought.”
@ The Guardian UK
