Ureaplasma is a type of bacteria commonly found in the urinary or genital tract. It does not usually cause symptoms, but in some cases, it may contribute to infections, fertility problems, or pregnancy complications.

Ureaplasma bacteria are part of the body’s bacterial population. In most cases, they live in balance with other microbes without causing a problem. However, sometimes they can increase in population, which can lead to health conditions.

This article examines what Ureaplasma is, how it transmits, the symptoms it can cause, and what treatment options are available.

A note about sex and gender

Sex and gender exist on spectrums. This article will use the terms “male,” “female,” or both to refer to sex assigned at birth. Click here to learn more.

Was this helpful?

Ureaplasma belongs to a class of bacteria known as Mycoplasma. They are among the smallest known organisms of their type that can make a copy of themselves to reproduce.

Many people who have Ureaplasma in their bodies are unaware. However, Ureaplasma can be opportunistic and may grow in higher numbers and cause infection if the circumstances allow.

If this happens, Ureaplasma may contribute to conditions that affect the male and female reproductive systems, such as infections or fertility problems.

However, scientists are still researching the role Ureaplasma may play in medical conditions.

A person can acquire Ureaplasma through sexual contact. It can also pass to newborns during pregnancy.

However, the prevalence of Ureaplasma varies widely depending on geographic location and socioeconomic background.

Although it may potentially play a role in some diseases, it is also far less likely to become harmful than other sexually transmitted pathogens, such as the bacteria that cause chlamydia.

Ureaplasma does not usually cause symptoms if it is living in balance with other bacteria. A healthy immune system can keep the bacteria in check, preventing them from causing infection.

However, certain health issues may develop if Ureaplasma colonizes part of the body. These could include:

Bacterial vaginosis

A 2022 study of 1,155 females of reproductive age found that the presence of Ureaplasma had a strong association with an increased pH level in the vagina.

Usually, the pH of the vagina is low, and the acidity prevents infections. However, a high or alkaline pH can allow harmful bacteria to grow in higher numbers, such as Gardnerella vaginalis, the bacteria that cause bacterial vaginosis (BV).

Symptoms of BV include:

  • itchiness
  • burning
  • fishy-smelling discharge
  • pain or discomfort

Ureaplasma also has links to chronic endometritis and pelvic inflammatory disease.


Ureaplasma may cause urethritis in males, which is inflammation of the urethra. Doctors refer to this as “nonchlamydial nongonococcal urethritis” or “nonspecific urethritis.”

The role of Ureaplasma in urethritis is still controversial, as this bacteria also occurs in healthy males. However, a 2019 review of the research states there is mounting evidence that Ureaplasma can cause urethritis under certain conditions, although it is not the most common cause.

Symptoms of urethritis may include:

  • white or cloudy discharge from the top of the penis
  • difficulty urinating
  • pain or burning when urinating
  • itchiness or irritation at the top of the penis

Low sperm count

A 2023 study of data from 2019–2021 found that Ureaplasma urealyticum, which is a specific type of Ureaplasma, had associations with lower sperm quality.

In 1,064 males between 20 and 30 years old, the presence of U. urealyticum correlated with lower sperm concentrations in semen and a lower ratio of sperm that can effectively swim.

Both of these factors influence male fertility and the likelihood that a sperm will fertilize an egg.

Difficulty getting pregnant

Ureaplasma may also cause fertility difficulties in females. This may occur if the bacteria reach the upper genital tract, which includes the uterus, fallopian tubes, and ovaries.

Scientists have yet to prove that Ureaplasma directly causes infertility, and research on the subject is mixed. A 2020 study of 245 females found that bacterial colonization of the fallopian tubes by any of the species the scientists examined had associations with tubal factor infertility, including U. urealyticum.

Tubal factor infertility is when a blockage in the fallopian tubes prevents sperm and egg from meeting.

However, a 2021 review of previous research found no association between U. urealyticum and female infertility. The authors recommend more research on a potential relationship with U. parvum instead.

Other conditions

Scientists are still investigating the potential link between Ureaplasma and other conditions. The bacteria may link to:


Prostatitis is inflammation of the prostate gland, which can cause:

A 2020 study found an association between Ureaplasma and calcification in the prostate, which may lead to chronic inflammation. However, a 2019 case-control study did not find a definitive link.


This condition occurs when tissue similar to the lining of the uterus grows elsewhere, which can cause pain, bloating, and heavy periods.

A 2019 laboratory study in mice found evidence that Ureaplasma infection increases inflammation in the uterus and may promote the development of endometriosis. However, much more research is necessary to determine the role of Ureaplasma, if any, in humans with endometriosis.

Ureaplasma has links to several pregnancy complications and conditions that affect newborn babies.

Ureaplasma risks in pregnancy

Ureaplasma infection has associations with:

  • Early membrane rupture: A 2020 study found a link between Ureaplasma and early membrane rupture. This is when the membrane surrounding the amniotic fluid breaks before a person is ready to give birth.
  • Preterm birth: Early membrane rupture can cause a premature birth. BV and other infections also raise this risk.
  • Chorioamnionitis: This is an infection of the contents of the uterus during pregnancy. It usually occurs in people whose amniotic fluids break too early, but it can also happen in those with an intact membrane. A 2021 study found that while many bacteria have associations with this infection, Ureaplasma was the most common in their sample.
  • Pregnancy loss: Scientists have found that certain species of Ureaplasma are prevalent among some people who experience pregnancy loss. For example, a 2020 study found that in people who experienced pregnancy loss, 66.3% had Ureaplasma parvum in the placenta. Overall, treatable genital tract infections cause 15% of early pregnancy loss and 66% of late pregnancy loss.

That said, previous research has estimated as many as 80% of pregnant people have Ureaplasma in the lower genital tract, so its presence in the body is very common. Scientists are still learning about the relationship between this bacteria and pregnancy complications.

Ureaplasma risks for newborns

Newborns have less developed immune systems than adults, and so Ureaplasma levels that do not affect the birth parent could potentially be more harmful for them.

An acute and invasive Ureaplasma infection could lead to complications such as pneumonia, meningitis, or sepsis.

A chronic infection may cause inflammation, which could contribute to bronchopulmonary dysplasia. This is when the lungs do not develop as they should before birth, or after birth if the baby is premature.

However, it is important to note that the presence of Ureaplasma is very common in adults and that this alone is not enough to cause an infection. Ureaplasma is more likely to become a problem in high numbers, and appears to be more of a risk for preterm babies.

Ureaplasma can be difficult to culture, so doctors may use PCR tests instead of trying to visually identify the bacteria.

PCR tests work by revealing if the bacteria’s DNA is present in a sample of bodily fluid. Depending on the situation, this sample could be:

The treatment for Ureaplasma is antibiotics. However, only certain antibiotics are effective against these bacteria.

Doctors choose the antibiotic based on the health condition a person has, whether they are pregnant, and their age, as some antibiotics are not safe for pregnancy or newborn babies.

For example, a doctor may prescribe:

  • macrolide antibiotics, such as clarithromycin, azithromycin, and erythromycin
  • tetracyclines, such as doxycycline
  • some fluoroquinolones

Sometimes, bacteria can become resistant to certain antibiotics. If the infection does not respond to one type of antibiotic, doctors may try another.

Ureaplasma is present in many people and does not usually cause problems. That said, the methods that can prevent transmission of Ureaplasma can also prevent sexually transmitted infections (STIs), so it is advisable to practice them.

This includes:

It may also help to support the body’s natural defenses against infection by protecting the pH balance of the genitals. People can do this by:

  • gently washing only the outside of the genitals with water
  • wearing clean, breathable underwear
  • changing out of sweaty or dirty clothes promptly

Although many personal hygiene products for the genitals are available, a 2021 report emphasizes that all soaps alter the pH of the vulva, with the exception of lactic acid-based gels. This can increase the risk of BV and other infections.

When cleaning the vulva, people should avoid:

  • scrubbing with flannels or cloths
  • using baby wipes, antibacterial wipes, perfumes, deodorants, or other products not formulated for the area
  • using soap or other products inside the vagina
  • douching

The outlook for Ureaplasma infection depends upon the health issues it is causing and the severity of the condition. Certain antibiotics are effective against the bacteria.

People with any unusual symptoms affecting the genitals or reproductive organs should speak with a doctor for a diagnosis.

If they are pregnant, have a compromised immune system, or are concerned for their baby, they should seek medical help right away, especially if they have signs of an infection.

Ureaplasma is a type of bacteria present in many people. It usually does not cause any problems, but in some people, it can colonize parts of the body and cause infections.

In females, Ureaplasma may change the vagina’s pH and contribute to BV. In pregnancy and newborns, it can sometimes lead to serious complications.

Scientists are still learning about other conditions where Ureaplasma may play a role.