Ureaplasma is a common bacterium belonging to the Mycoplasma family, frequently found in the genitourinary tract of sexually active adults. These organisms, primarily Ureaplasma urealyticum and Ureaplasma parvum, lack a cell wall, making them resistant to many standard antibiotics like penicillin. While often a harmless part of the normal microflora, their presence during pregnancy is concerning due to the potential for adverse outcomes if they proliferate or ascend into the uterus. Most women who carry this bacterium remain asymptomatic, but overgrowth of Ureaplasma species may contribute to specific pregnancy complications requiring medical management.
Understanding Ureaplasma and Its Prevalence
Ureaplasma species are minute bacteria that colonize the vagina, cervix, and urethra, often without causing noticeable signs of infection. The two main species, Ureaplasma urealyticum and Ureaplasma parvum, are generally transmitted through sexual contact, establishing a presence in a large percentage of the sexually active population. Studies suggest that between 40% and 80% of sexually active women may be colonized.
In many women, the bacteria live in balance with the rest of the vaginal microbiome, but a shift can lead to an opportunistic infection. The bacteria can also be transmitted vertically from the mother to the newborn during birth as the baby passes through the birth canal. Although common, Ureaplasma becomes a concern for pregnancy health only when it multiplies significantly or ascends into the upper reproductive tract.
Associated Pregnancy Complications
The primary risk associated with active Ureaplasma infection during pregnancy is its link to preterm birth (delivery before 37 weeks of gestation). When the bacteria ascend from the lower genital tract, they can infect the amniotic fluid, placental membranes, and the placenta itself. This invasion triggers a localized inflammatory response, which can lead to the premature rupture of membranes (PROM) and the onset of labor.
Infection of the placental membranes is known as chorioamnionitis, a condition often caused or contributed to by Ureaplasma species. This inflammation compromises the integrity of the pregnancy environment, increasing the risk of early membrane rupture and preterm delivery. The presence of Ureaplasma in the amniotic fluid has been shown to increase the risk of preterm delivery significantly in some studies.
Ureaplasma infection has also been associated with an increased risk of miscarriage, especially in the first and second trimesters, and stillbirth. The inflammatory environment created by the infection is disruptive to the normal progression of gestation. Risks to the newborn, particularly preterm infants, include congenital pneumonia, meningitis, and chronic lung disease, such as bronchopulmonary dysplasia.
Testing and Management Protocols
Routine screening for Ureaplasma in all pregnant women is not universally recommended because the bacteria are common and often harmless. Testing is usually reserved for women with a history of adverse pregnancy outcomes, such as recurrent miscarriage or prior preterm birth. It is also used for those who present with signs of potential infection, like preterm labor or premature rupture of membranes.
Diagnostic methods include specialized culture media for samples collected via cervical or vaginal swabs. Molecular techniques, such as Polymerase Chain Reaction (PCR) assays, are increasingly utilized for greater accuracy.
If an infection is suspected or confirmed in a high-risk scenario, treatment involves specific antibiotics safe during pregnancy. Since Ureaplasma lacks a cell wall, antibiotics like penicillin are ineffective. Tetracyclines are avoided due to the potential for harm to the developing fetus. Preferred treatments are macrolide antibiotics, such as erythromycin or azithromycin, which are active against Ureaplasma species and generally safe for use during gestation.
Treatment aims to eradicate the infection and reduce the bacterial burden, decreasing the potential for ascending infection and inflammation. Healthcare providers often recommend treating the patient’s sexual partner to prevent reinfection, as transmission is commonly through sexual contact. Although studies have not conclusively proven that treating all colonized women prevents preterm birth, antibiotic therapy is commonly employed when the infection is linked to a known complication.