Couples participating in a Swedish study were one-third less likely to achieve a pregnancy if the man had a history of infection with chlamydia.
Infertile couples in the study were more likely to have had chlamydia infections in the past than those who did not have trouble conceiving, and the frequency of persistent infection among the infertile couples was also much higher. The findings are reported in the May issue of the journal Human Reproduction.
"Chlamydia infection among men is clearly something that should be considered when couples are first seen for infertility," researcher Jan Olofsson, MD, PhD, tells WebMD. "In the Western world the occurrence of chlamydia infection is rising quite dramatically, and this could certainly impact fertility."
Chlamydia trachomatis is the most common sexually transmitted bacterial infection, with 3 million new cases estimated to occur each year in the U.S alone. Although often perceived as a female health problem, recent studies show that infection rates among men equal those among women.
Chlamydia infection in women usually has no symptoms. But if present, they include:
- Painful urination
- Abnormal vaginal discharge
- Genital itching
- Cloudy urine
- Lower abdominal pain
- Vaginal bleeding with intercourse or between periods
Men with chlamydia infection may have the following symptoms:
Persistent, untreated infection in women can progress to pelvic inflammatory disease, a leading cause of infertility in women. But the impact of current or past infection among men on their partners' ability to get pregnant has not been clear.
20% of Men Had Antibodies
In this study, Olofsson and colleagues tested 244 infertile couples for antibodies that indicated past chlamydia infections. In cases where one partner was positive they also tested for current infection. All couples were then followed for an average of three years.
Nearly one in four infertile women showed evidence of past infection, compared with one in seven women who had no trouble conceiving (these women were included in the trial as controls). One in five male partners of women who could not conceive showed evidence of past infection.
The researchers found that a couple's chance of achieving a pregnancy was reduced by 33% if the male partner had antibodies against chlamydia present in their body. The presence of the antibodies among the infertile women was linked to fallopian tube damage, which is a leading cause of infertility. But no such association was seen for men.
Routine Testing: Warranted or Not?
The authors suggest this finding indicates that some other, not yet identified, cause may explain how past or persistent chlamydia infection among men could compromise their partners' ability to get pregnant. They concluded that early infertility work-ups should include chlamydia antibody testing for both partners instead of just the woman, as is now the common practice.
But male infertility expert Larry Lipshultz, MD, tells WebMD that the study did not convince him that this change in clinical practice is warranted. Lipshultz is a professor of urology at Houston's Baylor College of Medicine.
"Based on this limited data, I would not be in favor of testing everybody for chlamydia," he says. "The people in this study were not tested for other sexually transmitted diseases that could impact fertility, so it is not really clear if this was a cause-and-effect relationship."
Chlamydia is easily treated with antibiotics, but it is not clear if treating antibody-positive infertile couples increases their likelihood of conceiving.
"This study raises some interesting questions, but it doesn't really answer them," Lipshultz says.