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IN a contradiction of conventional wisdom on the subject, research has shown those who do not have sex often produce sperm of lower quality than those who do so daily.
International researchers, including Australian doctors, believe sperm's DNA becomes more damaged the longer it remains in the body, cutting the chances of fertilisation and raising the risk of a miscarriage in the first weeks of pregnancy.
The findings, presented at the American Society for Reproductive Medicine's annual conference, will be of particular significance to couples undergoing fertility treatment.
Men are currently advised to stop having sex in the days before they provide a sperm sample for IVF treatment.
Until now, abstaining from sex in the three to seven days before treatment was thought to increase the quantity of sperm produced and improve the chances of pregnancy.
Australian researchers looking at the sperm quality of more than 40 men whose wives had either failed to get pregnant through IVF or had repeatedly miscarried found that when the men had no sex for three days, their sperm contained high levels of DNA damage.
Tested again after having sex every day for a week, the amount of damage dropped by a third.
While the amount of sperm produced had also fallen, fertility doctors said the improvement in quality would help men in their quest for fatherhood.
Researcher Dr David Greening, from the clinic Sydney IVF clinic, said: "I'm convinced ejaculating more frequently reduces sperm DNA damage in most men."
Dr Allan Pacey, a male fertility expert from Sheffield University and secretary of the British Fertility Society, said the research appeared to suggest that sperm sitting in the body accumulates damage as it ages.
He added: "If sperm is released in a steady stream, the sperm that is ejaculated contains newer and less- damaged cells."
