Effect of bidet toilet use on preterm birth and vaginal flora in pregnant women

OBJECTIVE: To estimate the association between bidet toilet use and preterm birth, as well as the effect of bidet toilet use on bacterial vaginosis, in pregnant women. METHODS: Questionnaires about bidet toilet usage were sent to 2,545 women who gave birth between 2006 and 2010 in Tokyo. Crude and multivariable adjusted odds ratios (ORs) for the incidence of preterm birth (delivery at less than 37 completed weeks of gestation) and the prevalence of bacterial vaginosis between users and nonusers of the bidet toilet were calculated using data from the questionnaire and delivery records. Bacterial vaginosis was estimated by the balance of lactobacilli and non-lactobacillus microbes based on routine prenatal micro-biologic test results. RESULTS: Of 1,293 women who responded to the questionnaire, 63.3% were users of the bidet toilet. The incidence of preterm birth was 15.8% among bidet users and 16.0% among nonusers (adjusted OR 1.04, 95% confidence interval [CI] 0.72-1.48). Additionally, no association was found between bidet toilet use and bacterial vaginosis (adjusted OR 0.96, 95% CI 0.70-1.33). CONCLUSION: Normal use of the bidet toilet by pregnant women poses no clinical health risk for preterm birth and bacterial vaginosis.