Vaginal examination, sampling and laboratory examination
A professionally trained clinician will perform vaginal examination and collect vaginal secretions for pregnant women under bladder stones gesture and record the reproductive tract signs after physical examination in the questionnaire immediately. The doctor used a non-lubricated sterile speculum and a sterile long cotton swab to collect 3 swabs of vaginal secretions on the upper vaginal wall or posterior fornix. The secretions were immediately transferred to the laboratory for pH test, normal saline wet film phase contrast microscope (Olympus, Japan) (400×) examination and Gram stain smear microscope (1000×) examination for the diagnosis of AV, BV, VVC, and TV. Blind laboratory examinations were performed by two experienced and trained laboratory technicians, who did not know the clinical data.