In a study of 118 Australian men with damaged sperm, doctors found that having sex every day for a week significantly reduced the amount of DNA damage in their patients' sperm. Previous studies have linked better sperm quality to higher pregnancy rates.
The research was announced Tuesday at a meeting of the European Society of Human Reproduction and Embryology in Amsterdam.
Dr. David Greening of Sydney IVF, a private fertility clinic in Australia, and colleagues looked at 118 men who had damaged sperm. Greening and colleagues told the men to have sex every day for a week. After seven days, the doctors found that in 81 percent of the men, there was a 12 percent decrease in the amount of damaged sperm.
Many fertility experts suggest men abstain from sex before their partners have in-vitro fertilization, to try to elevate their sperm counts.
Sperm quality can also be improved if men don't smoke, drink moderately, exercise, or get more antioxidants.
Since concluding the study, Greening says he now instructs all couples seeking fertility advice to start by having more sex. "Some of the older men look a little concerned," he said. "But the younger ones seem quite happy about it."
Experts think sex helps reduce the DNA damage in sperm by getting it out of the body quickly; if sperm is in the body for too long, it has a higher chance of getting damaged.
Some experts said that while Greening's research is promising, it doesn't prove that daily sex for men with fertility problems will actually produce more babies.
Greening said he and his colleagues are still analyzing the study data to determine how many women got pregnant.
"Looking at sperm DNA is just one part of the puzzle," said Bill Ledger, a professor of obstetrics and gynecology at the University of Sheffield, who was not connected to the research. "Maybe this will improve pregnancy rates, but we still need to do more studies."
Ledger said instructing couples with infertility problems to have more sex could stress their relationship. "This may add even more anxiety and do more harm than good," he said. He said couples shouldn't feel pressured to adjust their sex lives just for the sake of having a baby.
Greening said the study's findings were ultimately very intuitive. "If you want to have a baby, our advice is to do it often."