Ureaplasmas are tiny bacteria that live in the urinary and genital tracts. About a third of sexually active people carry them, usually with no symptoms and no ill effects. They have been linked to male infertility, but the evidence that they cause it is limited. For most men, carrying ureaplasmas is not a problem and does not need treating. Here is what is known about ureaplasmas, how they relate to fertility, and when testing is worth considering.
What are ureaplasmas?
Ureaplasmas are the smallest bacteria that can colonise and infect the human body. Their small size and other characteristics make them difficult to detect, and they are often overlooked by standard laboratory testing.
Ureaplasmas depend completely on urea for energy, and urea is concentrated in urine, so ureaplasmas are commonly found in the urogenital tracts of males and females.
How common are ureaplasmas?
Around one third of sexually active men and women have ureaplasmas in their urogenital tracts, usually without any symptoms. The presence of ureaplasmas in so many people without associated health effects suggests they are ‘commensal’ (living within the host without causing disease).
Are ureaplasmas an STI?
Ureaplasmas can be passed between sexual partners but because they are not considered ‘pathogenic’ (causes of disease), this is not considered a sexually transmitted infection.
Can ureaplasmas cause infertility?
Ureaplasmas are associated with infertility in males and females but proof that ureaplasmas cause infertility is limited. The shape and movement of sperm might be affected by ureaplasmas, which would be expected to reduce fertility. Also, ureaplasmas can stick to sperm, which might also affect their function. For males and females, inflammatory responses to ureaplasmas may impair fertility.
What are the symptoms of ureaplasma in men?
High ureaplasma ‘loads’ (lots of ureaplasmas) are associated with inflammation of the urethra (urethritis) in men but most men with ureaplasmas do not get urethritis, and urethritis in most men is cause by other microorganisms. Prostatitis may also be attributed to ureaplasmas.
Should you be tested for ureaplasmas?
Ureaplasma is not usually included in standard sexually transmissible infection (STI) testing, or in the tests done when couples are investigating infertility. This is partly because ureaplasmas are so common in people with no symptoms that a positive result can be hard to interpret. However, there is recognition that more studies are needed to improve our understanding of the role of ureaplasmas in sexual and reproductive health, and to better inform clinical testing.
If you are concerned about your fertility or think you may have an STI, talk to your GP or a sexual health clinic about which tests are appropriate for you.
Can ureaplasmas be treated?
Not all antibiotics work against ureaplasmas and, like for many different bacteria, antibiotic resistance is a problem. The most common antibiotics used to treat ureaplasma infections, doxycycline and azithromycin, are not always effective, making it difficult to eradicate them. Fortunately, getting rid of ureaplasmas completely is not always necessary for relief of symptoms.
What you should do if you’re worried about your fertility
Start with your GP. You’ll discuss how long you’ve been trying to conceive, your medical history, they’ll do a physical examination and might send you for more tests, like a semen analysis. If you have symptoms like pain, discharge or burning when you urinate, mention those too, since STI testing may be worthwhile.
Ureaplasma testing is not part of a standard fertility workup, and a positive result is difficult to interpret given how common ureaplasmas are in people with no problems. If you have read about ureaplasma and want to know whether it applies to you, raise it with your GP or fertility specialist.
Fertility is a shared issue. If you are trying to conceive as a couple, it is worth both of you being assessed rather than starting with one partner.
People also ask
Can ureaplasma make men infertile?
Ureaplasmas are found more often in men and women with fertility problems, but that does not mean they are the cause. Proof that ureaplasmas cause infertility is limited.
What should men avoid before trying to conceive?
Smoking, heavy drinking, recreational drugs and anabolic steroids can all affect sperm quality. Sperm take around three months to develop, so making changes a few months before you start trying gives them time to take effect. Learn more about boosting your sperm count and improving fertility here.
Tim Moss
Healthy Male Health Content Manager
Dr Tim Moss has PhD in physiology and more than 20 years’ experience as a biomedical research scientist. Tim stepped away from his successful academic career at the end of 2019, to apply his skills in turning complicated scientific and medical knowledge into information that all people can use to improve their health and wellbeing. Tim has written for crikey.com and Scientific American’s Observations blog, which is far more interesting than his authorship of over 150 academic publications. He has studied science communication at the Alan Alda Centre for Communicating Science in New York, and at the Department of Biological Engineering Communication Lab at MIT in Boston.
