Men should ejaculate more, say scientists
Monday, 15 October 2007
Scientists today recommended men should ejaculate more often if they want to keep their sperm healthy.
Research showed that men who had some form of sexual activity daily had better quality sperm than a control group who had been told to abstain for three days at a time.
The study was aimed at helping couples improve their chance of getting pregnant and concluded that men cut their chances if they hold off sexual activity.
But the Australian research shows the chances of pregnancy are lower if a couple waits for long stretches between sex sessions.
A study found that getting men with damaged sperm to ejaculate daily improved its quality when couples were undergoing IVF.
Researchers in Sydney studied 42 men with abnormal sperm structure whose partners had suffered repeated miscarriages or failed IVF attempts.
The men were told to ejaculate daily for seven days and these samples were compared with ejaculation after three days of abstinence.
A total of 37 patients had less sperm damage - or DNA fragmentation - if they ejaculated daily compared with after three days, the study found.
The research was presented at the American Society for Reproductive Medicine conference in Washington DC.
Dr Allan Pacey, senior lecturer in andrology at the University of Sheffield and secretary of the British Fertility Society, said it was important to understand the "trade-off" between genetic damage to the sperm and quantity.
He said: "If you get above 30 to 40% damaged DNA, a man is highly likely to be infertile.
"There is a population of men who have a history of IVF failure and miscarriage in their partners, in whom there is an underlying concern about the DNA quality in their sperm.
"This research shows that when you put people on a daily ejaculation regime, it reduces that figure for DNA damage.
"If you can go from 30% down to 20% that is quite a big shift and that should have implications for fertility."
Dr Pacey said some couples believed they had a better chance of achieving pregnancy if they waited a long time between making love.
"There are men out there who think, or whose partners think, that limiting ejaculation will make them more fertile," he said.
"I remember one couple in which the woman would only let the man ejaculate when she was in her fertile period, so the poor chap was going without for almost a month at a time.
"But if sperm is released in a steady stream, the sperm that is ejaculated are newer and less damaged.
"There is a trade-off between genetic damage and quantity, so when a couple is first trying to get pregnant a wait of two to three days is probably advisable.
"But if you are a guy who has high DNA damage and a decent sperm count, it is probably in your interest to ejaculate every day.
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