Ureaplasma and Fertility: The Silent Infection Sabotaging Conception and Pregnancy

Brittany Hancock
Jun 5
4 min read

Many women struggling to conceive or experiencing early pregnancy loss are told that everything looks "normal" by their GPs. But behind the scenes, hidden infections can quietly disrupt reproductive health even WITHOUT obvious symptoms. One of the most overlooked infections is Ureaplasma. It is a stealthy bacterial infection that can alter your vaginal microbiome, inflame your uterus, and interfere with fertility in so many ways! So if you have been struggling to get pregnant after 3 cycles you might want to test this!

What is Ureaplasma?

Ureaplasma species, including Ureaplasma urealyticum and Ureaplasma parvum, are cell wall-deficient bacteria that belong to the Mollicutes class. Their lack of a peptidoglycan cell wall makes them naturally RESISTENT to many standard antibiotics. So you might think I can’t have an infection I have had a round of anti-biotics, well actually this can make it worse. Because now you have wiped out the beneficial bacteria. While Ureaplasma can live harmlessly in some individuals, they are considered opportunistic pathogens and can trigger a cascade of problems when the vaginal environment is out of balance. These organisms typically colonise the urogenital tract and are transmitted sexually or vertically from mother to child during birth.

Unlike traditional infections that produce symptoms, Ureaplasma often causes low-grade, chronic inflammation that goes undetected or you might think this is partly just your “normal” well its NOT!

Now just to be clear some GPs don’t even test for this. In fact I have a client working with her fertility doctor who did some routine swabs and urine culture and everything came back clear and then we did a vaginal microbiome and she had no beneficial bacteria and a Ureaplasma infection which was likely the cause of her long-term pelvic pain.

How Ureaplasma Affects Fertility

Ureaplasma can impact fertility through several mechanisms. Firstly, it alters the vaginal microbiome. A healthy vaginal ecosystem is dominated by Lactobacillus species, which maintain a low pH via producing lactic acid. This acidity prevents the overgrowth of harmful organisms and supports sperm survival. When Ureaplasma takes hold, it disrupts this balance, increasing vaginal pH and allowing opportunistic microbes such as Candida albicans and Gardnerella vaginalis to thrive. The resulting shift toward a more alkaline environment compromises cervical mucus quality and mucosal immunity, creating a less hospitable setting for both sperm and implantation. When you don’t have a hospitable environment you might just be able to implant but you won’t keep it. This happened to another one of my clients, she had a chemical pregnancy and was pregnant but was unable to keep the pregnancy and the vaginal microbiome here reflected no infections which was great but beneficial bacteria was non-existent! If you have had a chemical pregnancy maybe this is why!

Secondly, Ureaplasma activates the immune system. Its presence triggers neutrophil recruitment, production of inflammatory cytokines such as IL-1β and TNF-α, and damage to the epithelial barrier of the reproductive tract. This chronic inflammation can reduce endometrial receptivity and create a hostile uterine environment. In some cases, it may even lead to autoimmune activation, increasing the risk of endometriosis or pelvic pain syndromes.

Thirdly, Ureaplasma can directly damage sperm. Studies have shown that the bacteria can attach to spermatozoa, impair their motility, and even induce DNA fragmentation. Infections in seminal fluid also increase oxidative stress, reducing fertilisation potential.

Lastly, Ureaplasma is linked to tubal factor infertility. Inflammation associated with infection can cause subclinical salpingitis, potentially resulting in scarring, adhesions, or blockage of the fallopian tubes, which limits egg transport and the chances of conception.

The Link Between Ureaplasma and Pregnancy Loss

Even when conception occurs, Ureaplasma may still affect pregnancy outcomes. One mechanism is via microbial translocation. The bacteria can ascend through the cervix and colonise the placenta and fetal membranes, potentially causing chorioamnionitis. This inflammatory response is associated with early miscarriage, preterm labour, and low birth weight. Even women who are able to get pregnant and maintain the pregnancy who still be affected by this and impact the outcomes of the child.

Ureaplasma also affects the maternal immune system. During pregnancy, a delicate immune shift occurs to allow tolerance of the fetus. Ureaplasma disrupts this by increasing pro-inflammatory Th1 cytokines such as IFN-γ, which can compromise the immune of the placenta and trigger fetal rejection.

Additionally, Ureaplasma often exists alongside other organisms involved in bacterial vaginosis, such as Gardnerella vaginalis.

BV has been strongly linked to early pregnancy loss and failed implantation. It is believed that low-grade, chronic inflammation in the uterine lining damages the decidua and trophoblast cells, impairing proper placental development.

Why Partner Treatment Matters

Treating Ureaplasma must include both partners. If you are positive for this, it is important the male is also tested. However, note that male partners often test negative in standard urine tests, yet may carry Ureaplasma in their semen, making them a persistent source of reinfection. Some GPs will allow semen testing but it just depends. Men are frequently asymptomatic, Ureaplasma can contribute to unexplained infertility, urethritis, and pelvic discomfort. Unless both partners are treated simultaneously, the infection can continue to cycle back and forth.

The Role of the Vaginal Microbiome

A healthy vaginal flora is not only important for preventing infection but also plays a crucial role in regulating the immune system, maintaining a low vaginal pH, and supporting implantation. When Lactobacillus species are depleted, it leaves space for pathogens like Ureaplasma to overgrow. This triggers mucosal immune dysregulation and systemic inflammatory effects, which can contribute to autoimmune flares, chronic pelvic symptoms, and reproductive dysfunction.

Next Steps

If you've experienced recurrent pregnancy loss, difficulty conceiving, or unexplained inflammatory symptoms, it's worth investigating whether a hidden infection like Ureaplasma is part of the picture or even other infections. Standard medical testing often misses this organism, especially when symptoms are mild or absent.

As a naturopath, I use advanced vaginal microbiome testing via NutriPath to detect these underlying imbalances and create a treatment plan based on restoring microbial and immune harmony.

Book your consult and vaginal microbiome test today to uncover what’s really going on beneath the surface!

Book Now