New research suggests that men might actually boost their fertility by having more frequent ejaculations. Scientists have discovered that sperm quality can decline the longer it remains stored within the body, showing signs of damage and reduced viability over time. This finding could have significant implications for fertility treatments and how couples approach trying to conceive.
The Science Behind Sperm Deterioration
The research, which involved a comprehensive meta-analysis of 115 human studies encompassing almost 55,000 men, alongside 56 studies examining 30 non-human species, found a consistent trend. In both humans and other animals, sperm tended to deteriorate while stored within the male, irrespective of the individual’s age.
Dr. Krish Sanghvi, a biologist at the University of Oxford and the lead author of the study, explained the significance of these findings. “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,” he stated.
The study specifically observed that the longer men abstained from ejaculation, the more their sperm exhibited signs of DNA damage and oxidative stress. This deterioration was also reflected in tests that rated the sperm’s viability and motility – essentially, how well they swam.
Re-evaluating Fertility Guidelines
Current guidelines from the World Health Organization (WHO) typically recommend that men abstain from ejaculation for two to seven days before providing sperm for fertility tests or in vitro fertilisation (IVF). However, these guidelines were primarily developed to ensure the highest possible sperm count, rather than prioritising the optimal quality of the sperm.
Dr. Sanghvi suggests that this approach may need a more nuanced perspective. “All we recommend is that clinicians and couples reconsider whether long abstinence is always good, because abstinence leads to deterioration in sperm quality,” he advised. The detailed findings of this research have been published in the journal Proceedings of the Royal Society B.
He further elaborated, “If sperm quantity is the only thing that matters for a clinic or couple, then sexual abstinence is not necessarily a bad thing. 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.”
Clinical Evidence and Practical Advice
While the Oxford study itself did not directly find an impact of abstinence duration on human fertilisation rates, a recent clinical trial involving 453 couples provided compelling evidence. In this trial, IVF doctors compared pregnancy outcomes between two groups of couples.
- Group 1: Men abstained from ejaculation for less than two days before providing sperm for IVF treatment.
- Group 2: Men followed the WHO recommendations and abstained for two to seven days before providing sperm.
The results were telling: the pregnancy rate was 46% for couples where the male had abstained for less than 48 hours, compared to only 36% in the group where men abstained for longer periods.
For couples who are trying to conceive naturally, finding the right balance is key. Abstaining for too long could lead to damaged and less mobile sperm, while abstaining for too short a period might result in sperm that are not sufficiently numerous or 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,” Dr. Sanghvi concluded.
Expert Opinion on Assisted Reproduction
Professor Allan Pacey, a leading andrologist at the University of Manchester, echoed these sentiments, noting the growing body of evidence supporting shorter abstinence periods for assisted reproduction.
“There has been growing evidence in recent years that a shorter abstinence time might be beneficial when undergoing assisted reproduction such as IVF,” Professor Pacey commented. “This is because with a short abstinence time the sperm are fresher, more motile and have lower levels of DNA damage.”
He clarified the role of the WHO guidelines: “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.”
Professor Pacey highlighted the advancements in assisted reproductive technologies (ART). “For assisted reproductive technology (ART) treatments, it’s having the freshest, most healthy sperm that is probably more important,” he stated. “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.”
This evolving understanding suggests that for many couples, especially those undergoing fertility treatments, a more frequent ejaculation pattern could be a simple yet effective strategy to enhance their chances of conception.
