To examine the association between colonization by two newly classified species of genital ureaplasmas (Ureaplasma parvum and U. urealyticum) in early pregnancy and subsequent late abortion or preterm birth at <34 weeks of gestation, four species of genital mycoplasmas-Mycoplasma genitalium, M. hominis, U. parvum, and U. urealyticum-as well as Chlamydia trachomatis and Neisseria gonorrhoeae were examined by PCR-based methods in a prospective cohort study of 877 women with singleton pregnancies at <11 weeks of gestation. Antibiotics were used only in cases in which C. trachomatis and/or N. gonorrhoeae was detected. Multivariate logistic-regression analysis was used to assess independent risk factors after taking maternal low body weight and past history of preterm birth into account. M. genitalium, M. hominis, U. parvum, U. urealyticum, C. trachomatis, and N. gonorrhoeae were detected in 0.8%, 11.2%, 52.0%, 8.7%, 3.2%, and 0.1% of these 877 women, respectively. Twenty-one (2.4%) women experienced late abortion or preterm birth at <34 weeks of gestation. Preterm birth and low birth weight are the leading causes of neonatal mortality and morbidity in the developed world. More than 60% of the mortality among infants without anatomic or chromosomal defects can be attributed to low birth weight (20). Ascending genital tract infections contribute to up to 50% of premature deliveries, particularly those occurring before 30 weeks of gestation (4, 15). Moreover, the rate of neonatal complications has been shown to be higher in neonates born to women with microbial invasion of the amniotic cavity than born to those women without infection (10).Genital mycoplasmas, including Mycoplasma hominis, M. genitalium, and Ureaplasma spp., are suspected of contributing to a number of pathological conditions. M. hominis was isolated from the amniotic fluid in 30% of 404 women with intraamniotic infection (21) and was shown to be associated with preterm birth at Ͻ33 weeks of gestation (23). M. genitalium was suggested to cause urethritis in men (11) and mucopurulent cervicitis in women (16), but its association with preterm birth has not been studied extensively. Ureaplasma has been implicated in infertility, spontaneous abortion, stillbirth, premature birth, low birth weight, and perinatal morbidity and mortality (3). Vaginal colonization with Ureaplasma has not been associated with preterm birth (3), while the presence of Ureaplasma in the amniotic fluid is associated with a robust host response in fetal, amniotic, and maternal compartments (24) and subsequent preterm birth (7). It is not known why this microorganism invades the amniotic cavity only in some women despite heavy colonization of the vagina by Ureaplasma.Recently, the species previously classified as Ureaplasma urealyticum was separated into two new species: U. parvum (previously U. urealyticum biovar 1) and U. urealyticum (previously U. urealyticum biovar 2) (14, 19). Therefore, U. urealyticum organisms examined in previous studies (3, 7, 24) may have included both U. p...

The impact of cytomegalovirus (CMV) infection of the genital tract during pregnancy on adverse pregnancy outcomes is not understood fully. A real-time PCR assay was used to determine vaginal shedding of CMV in 993 healthy pregnant Japanese women and the results were compared with the outcome of pregnancy. CMV DNA was detected in 76 (7.7%) of the women. The outcome of pregnancy could be determined finally in 848 women, of whom 60 (7.1%) were CMV positive. The carriers of CMV had an increased miscarriage rate (RR 6.96, 95% CI 2.04-23.84, P < 0.01). These findings suggest that latent genital tract CMV infection predisposes to adverse pregnancy outcomes.