Bacterial vaginosis was associated with the preterm delivery of low-birth-weight infants independently of other recognized risk factors.

After considering other recognized risk factors including co-infections, pregnant women infected with T. vaginalis at mid-gestation were statistically significantly more likely to have a low birth weight infant, to deliver preterm, and to have a preterm low birth weight infant. Compared with whites and Hispanics, T. vaginalis infection accounts for a disproportionately larger share of the low birth weight rate in blacks.

To study the role of infection in prematurity, we studied the demographic and obstetrical characteristics, chorioamnionic cultures, and placental histologic features of women who delivered prematurely and compared these findings with those in women who delivered at term. Microorganisms were isolated from the area between the chorion and the amnion (chorioamnion) in 23 of 38 placentas (61 percent) from women with preterm labor who delivered before 37 weeks' gestation and in 12 (21 percent) of 56 placentas from women without preterm labor who delivered at term (odds ratio, 5.6; 95 percent confidence interval, 2.1 to 15.6). The most frequent isolates from the placentas of those whose infants were delivered prematurely were Ureaplasma urealyticum (47 percent) and Gardnerella vaginalis (26 percent). The recovery of any organism from the chorioamnion was strongly associated with histologic chorioamnionitis (odds ratio, 7.2; 95 percent confidence interval, 2.7 to 19.5) and with bacterial vaginosis (odds ratio, 3.2; 95 percent confidence interval, 1.1 to 6.6). When multiple logistic regression was used to control for demographic and obstetrical variables, premature delivery was still related to the recovery of organisms from the chorioamnion (odds ratio, 3.8; 95 percent confidence interval, 1.5 to 9.9) and with chorioamnionitis (odds ratio, 5.0; 95 percent confidence interval, 1.6 to 15.3). The proportion of placentas with evidence of infection was highest among those who delivered at the lowest gestational age. We conclude that infection of the chorioamnion is strongly related to histologic chorioamnionitis and may be a cause of premature birth.

To evaluate whether bacterial vaginosis predicts the acquisition of sexually transmitted diseases (STDs), we studied 255 nonpregnant female subjects aged 15-30 who reported recent sexual contact with a male partner in whom either gonococcal or chlamydial urethritis or nongonococcal urethritis was diagnosed. Compared to subjects with normal vaginal flora, subjects with bacterial vaginosis were more likely to test positive for Neisseria gonorrhoeae (odds ratio [OR], 4.1; 95% confidence interval [CI], 1.7-9.7) and Chlamydia trachomatis (OR, 3.4; 95% CI, 1.5-7.8). Subjects colonized vaginally by hydrogen peroxide-producing lactobacilli were less likely to receive a diagnosis of chlamydial infection or gonorrhea than subjects without such lactobacilli. Bacterial vaginosis was a strong predictor of gonorrhea and chlamydial infection among subjects who reported recent exposure to a male partner with urethritis. These data support the importance of vaginal flora in the defense against STD acquisition.