Clamming up can cut off your heir supply

Chlamydia in a male partner lowers a couple's chances of conceiving

By Tony Crayg

Everyone knows what happens when she gets the 'clam' � slang for Chlamydia � but what about when he does? It's long been known that chlamydia can affect women's fertility, and potentially lead to arthritis and other problems, but now for the first time evidence has emerged that this most well-travelled of pathogens can also have a serious impact on men's fertility.

Researchers from Sweden's Umea University tested 244 infertile couples attending a fertility clinic for evidence of Chlamydia infection. They then monitored whether these couples conceived or not for an average of 37 months. As a control, the researchers also tested a matched group of women in the same age range, recruited from a local antenatal clinic. These women had all achieved spontaneous, rather than planned pregnancies. Their results suggest that male infection reduced a couple's chance of having a baby by around a third. Writing in the May issue of Human Reproduction, the researchers say this wasn't because the man passed the infection on to the woman. In fact, a Chlamydia-infected man reduced a couple's chances of getting knocked up more than an infected woman. As proof, couples in which the man was infected were 2.56 more likely to be infertile than the average, whereas couples in which the woman was infected were 1.55 times more likely to be infertile.

Chlamydia antibodies were found in nearly a quarter of the infertile women and a fifth of the infertile men but only in 15% of those who had conceived naturally. Seven percent of infertile men and 7% of infertile women who had the antibodies also carried Chlamydia DNA in their urine, suggesting active infection.

Antibodies in the women were related to tubal factor infertility (TFI), which affects the fallopian tubes. This confirms previous findings that Chlamydia is linked to TFI. But antibodies in men weren't significantly associated with TFI in their partners. This implies that there's some mechanism at work on the sperm itself. Lead author Jan Olofsson, PhD, suggested that "it is possible that decreased sperm motility or concurrent or undetected infection may play a role." Previously, it's been suggested that pathogens from the male were travelling to the female and causing tubal infertility or other damage. But such an explanation can't, on it's own, account for the pattern seen.

According to Professor Olofsson, these "findings show that it is not only women that need to be concerned about contracting Chlamydia. Men need to be aware that this is potentially serious for them as well." In light of these recent results and given the fact that as many as one in 10 young men are infected with Chlamydia, maybe it's time that both women and men attending fertility clinics be screened for Chlamydia.