Ureaplasma is a genus of commensal bacteria that lack a cell wall and can colonize the genital tract of sexually active women. Ureaplasma sp. may cause chorioamnionitis, preterm birth, and spontaneous abortion. Vertical transmission to infants may be asymptomatic or can cause pneumonia, sepsis, and meningitis. Diagnosis usually requires molecular techniques; treatment is usually with macrolide antimicrobials. There is an observed association between Ureaplasma and bronchopulmonary dysplasia but trials of Ureaplasma prophylaxis or treatment to reduce bronchopulmonary dysplasia rates have been equivocal.