Chlamydia, a common sexually transmitted disease and known cause of infertility in women, can also reduce a man’s chance of fathering a child, Swedish researchers said on Thursday.
“Men should be aware that they can attract the infection and they should get tested and treated for it,” said Jan Olofsson of the Scandinavian Fertility Center in Gothenburg.
In a collaborative study with scientists at Sweden’s Umea University Hospital of 244 couples treated for infertility, Olofsson discovered that a quarter of the women and a fifth of the men tested positive for antibodies that are a marker of chlamydia infection.
“We found that quite a high number of the couples with antibodies had an ongoing infection,” Olofsson added in a telephone interview.
After following the success of the couples for an average three years, the researchers found that antibodies for chlamydia were inversely associated to the overall pregnancy rate. Men with the antibodies had a 33 percent lower rate of fertility than those without them.
“It is quite a high figure,” Olofsson said.
About 92 million new cases of chlamydia were diagnosed in 1999, according to the World Health Organization. But because the illness often has no symptoms, about 70 percent of women and 50 percent of men do not know they have it.
Disease may impact sperm
The illness can be easily treated with antibiotics. If it is diagnosed and treated, it causes no lasting problems in women. But recurrent and severe infections can result in infertility, ectopic pregnancy, pelvic inflammatory disease and pain.
Babies exposed to the infection during birth may develop an eye infection or pneumonia.
Olofsson, who reported the findings in the journal Human Reproduction, said it is not known how chlamydia causes male infertility. Scientists believe it may have an impact on sperm but other mechanisms, and infections, could also be involved.
He advised men with fertility problems to be checked for the infection with a simple blood test and get treatment if they have it.
“I think men should be very worried about this. Men do not go for testing easily,” said Olofsson.
He also suggested routine testing for men and women undergoing fertility treatment. An estimated one in six couples suffers from infertility. In about half of cases it is due to a male problem.