Perinatal Ureaplasma urealyticum infection and colonization: the association with preterm delivery and the spectrum of disease in neonates

Ureaplasma urealyticum is a mycoplasma that commonly colonizes the lower reproductive tract of pregnant women and is transmitted vertically to their infants. Renewed interest in this organism in perinatal–neonatal medicine is based upon two observations: when U. urealyticum gains access to the upper genital tract it is associated with chorioamnionitis and preterm delivery; vertical transmission of U. urealyticum to very low birth-weight infants – resulting in colonization of their airways – is associated with the development of chronic lung disease and possibly other neonatal morbidities. The objectives of this review are to describe briefly the organism and new developments in identification and isolation, to present new concepts of the role Ureaplasma plays in the pathogenesis of preterm delivery, and to describe in detail the spectrum of disease processes due directly to infection with Ureaplasma or as a consequence of colonization in newborns, particularly very low birth-weight infants.