PERINATAL TRANSMISSION OF UREAPLASMA-UREALYTICUM - CURRENT CONCEPTS BASED ON REVIEW OF THE LITERATURE

Ureaplasma urealyticum is a common inhabitant of the urogenital tract of pregnant women. This mycoplasma is transmitted from a colonized wom an to her newborn infant in one of three ways: (1) in utero either tra nsplacentally from the mother's blood or by an ascending route seconda ry to colonization of the mother's urogenital tract; (2) at delivery b y passage through a colonized birth canal; and (3) postnatally by hori zontal or nosocomial transmission. The rate of vertical transmission r anges from 18% to 55% among full-term infants and from 29% to 55% amon g preterm infants. The rate of vertical transmission is not affected b y method of delivery but is significantly increased when chorioamnioni tis is present. Moreover, colonization of the infant with U. urealytic um occurs despite delivery by cesarean section with intact fetal membr anes; ureaplasmal infection of the amniotic sac without rupture of mem branes has been well described. Ultimately, the prevalence of infant c olonization will depend on the prevalence of maternal colonization in a given population. However, the rate of colonization appears to be hi gher in very-low-birth-weight (VLBW) infants. Given this finding, as w ell as the potential for serious disease that could be attributed to U . urealyticum in this population, it seems reasonable to target the VL BW infant for a clinical treatment trial to determine if eradication o f this organism will decrease the incidence of chronic lung disease.