A transvaginal ultrasound during menstruation is not infectious. Transvaginal ultrasound using high-frequency probes, the probe wearing a disposable condom, blocking pathogenic bacteria to prevent infection. Sterilizing coupling agent used inside and outside the condom is a regular special sterilizing coupling agent, and disposable condoms in regular hospitals, to ensure that each person each time a change, even if the same patient needs to repeat the operation, will also be replaced with a new condom. During the operation process, the ultrasonographer will change the disposable gloves for each patient and carry out aseptic operation to prevent nosocomial infections and cross-infections. For special cases, such as emergency cases during menstruation, heavy bleeding, acute severe inflammation, vaginal ultrasound must be performed, the ultrasonographer will be sterilized after the examination, and the aseptic operation will be strictly carried out. Unless there are special circumstances and emergency situations, try to avoid menstruation and heavy bleeding, or acute severe inflammation. Patients are reminded that vaginal examination can be performed 2-3 days after menstruation, and if the endometrial condition is observed, it is also better to perform the examination 2-3 days after menstruation.