Prospective study of bidet toilet use: Association of abnormal vaginal colonization and preterm birth in high‐risk pregnant women

This study aimed to evaluate the association of bidet toilet use with abnormal vaginal microbial colonization and preterm birth (PTB) in high-risk pregnancies.This is a prospective cohort study of 208 women, who were admitted to a high-risk pregnancy unit, due to preterm labor, preterm premature rupture of the membrane, or short cervical length, in two tertiary hospitals from April 2015 to July 2017. Responses to a questionnaire about using bidet toilet and vaginal culture were obtained upon admission. Maternal baseline characteristics, vaginal culture results, and pregnancy and neonatal outcomes were compared between bidet toilet users and nonusers.Among the 204 subjects, 67 (32.8%) women were identified as bidet toilet users. Overall, bidet toilet use was associated with a higher rate of abnormal vaginal microbial colonization, compared to the nonusers (60.7% vs 44.2%, P = 0.036). Notably, Escherichia coli colonization rate was significantly higher in bidet toilet users than nonusers (13.1% vs 3.3%, P = 0.023). Bidet toilet users had a significantly higher rate of PTB before 37 weeks of gestation, compared to the nonusers (87.3% vs 73.0%, P = 0.040).Our study suggests that chronic use of a bidet toilet is associated with a higher rate of abnormal vaginal colonization by Gram-negative bacteria and PTB in high-risk pregnancies.