Here's why i have so many Kids
Mark Henderson, Science Editor
Daily sex can improve the genetic quality of a man’s sperm and could raise his chances of fathering a child, research has suggested.
Couples who are trying for a baby are often advised to have sex every other day, so that the man’s sperm count has time to recover, but scientists in Australia have discovered that this may lower some men’s fertility.
While abstaining from sex for a few days raises the sperm count, quality can be damaged if a man ejaculates too infrequently. A study at Sydney IVF, a centre for infertility treatment, has found that daily sex for a seven-day period substantially improves the genetic quality of sperm, without lowering sperm counts enough to impair fertility.
David Greening, who led the research, said that for some couples having intercourse every day during the woman’s most fertile period could be crucial to starting a family.
The findings, which he presented yesterday at the European Society of Human Reproduction and Embryology conference in Amsterdam, could also have important implications for couples having IVF. Men are usually advised to abstain from ejaculation for three days before providing a sperm sample for fertilising their partner’s eggs and many couples do not have regular sex while going through IVF.
When men go without ejaculating, the number of sperm stored in the epididymis at the top of the testicle increases. The longer that sperm sits in the epididymis, however, the more genetic damage it accumulates through exposure to heat and to oxygen free radicals.
Dr Greening speculated that daily sex might be more fertile sex. “Through simply clearing the epididymis and testicles, DNA damage has less time to occur. There’s less time for vandalism.”
Two years ago, Dr Greening conducted a pilot study involving 42 men with high levels of DNA damage in their sperm. It found that daily ejaculation reduced DNA damage levels by 12 per cent.
He has repeated the experiment in a larger group of 118 men. Among 81 per cent of men, sperm DNA damage decreased by an average of 12 per cent, though DNA damage increased slightly in the remaining 19 per cent.
Dr Greening said that he had changed his advice to couples accordingly. “If I see a couple and the man has high DNA damage to his sperm, I do the seven-day test to see if it comes down,” he said.
