Relationship of bacterial vaginosis and mycoplasmas to the risk of spontaneous abortion.

OBJECTIVE This study was undertaken to investigate a possible link between first-trimester diagnosis of bacterial vaginosis and cessation of pregnancy at < or =20 weeks' gestation. STUDY DESIGN Women (n = 228) who received routine prenatal care in Flanders, Belgium, during the first trimester (14 weeks' gestation) and had a living singleton fetus were examined for microbiologic flora of the vagina. Bacterial vaginosis was assessed either clinically (Amsel et al criteria), microscopically (clue cells), or by culture of bacterial vaginosis-associated bacteria. Data were analyzed univariately (relative risk) and multivariately. RESULTS The presence of bacterial vaginosis at the first prenatal visit was strongly associated with subsequent early pregnancy loss (relative risk, 5.4; 95% confidence interval, 2.5-11). After multivariate analysis bacterial vaginosis, Mycoplasma hominis, and Ureaplasma urealyticum but not other microorganisms remained associated with an increased risk of miscarriage. CONCLUSION Bacterial vaginosis and mycoplasmas may play causative roles in spontaneous abortion and early pregnancy loss.