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Effect of Bidet Toilet Use on Preterm Birth and Vaginal Flora in Pregnant Women

Asakura, Keiko MD, MPH, PhD; Nakano, Makiko MD, PhD; Yamada, Mutsuko PhD; Takahashi, Kaori MD; Sueoka, Kou MD, PhD; Omae, Kazuyuki MD, PhD

doi: 10.1097/AOG.0b013e318291bc16
Original Research

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 nonlactobacillus microbes based on routine prenatal microbiologic 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.


Supplemental Digital Content is Available in the Text.Normal use of a bidet toilet by pregnant women does not pose clinical health risks with regard to preterm birth and vaginal flora.

Departments of Preventive Medicine and Public Health and Obstetrics and Gynecology, Keio University School of Medicine, Shinjuku-ku, Tokyo, Japan.

Corresponding author: Keiko Asakura MD, MPH, PhD, Department of Preventive Medicine and Public Health, Keio University School of Medicine, 35 Shinanomachi, Shinjuku-ku, Tokyo 160-8582, Japan; e-mail:

Supported by the Japan Toilet Seat Appliances Association.

Financial Disclosure The authors did not report any potential conflicts of interest.

© 2013 by The American College of Obstetricians and Gynecologists. Published by Wolters Kluwer Health, Inc. All rights reserved.