Transabdominal ultrasound can be performed during menstruation. Transabdominal gynecological examination is generally not recommended during menstruation, as the endometrium sheds to form a traumatic surface during menstruation, and transabdominal ultrasound examination may increase the chance of infection at this time. However, certain diseases require ultrasound examination during menstruation to facilitate disease diagnosis, as follows: 1. Basal follicle monitoring is performed on days 2-5 of menstruation; 2. Examination of endometrial conditions, such as thickness and presence of cyclic hyperplasia, is required during menstruation; 3. Irregular vaginal bleeding, dripping with abdominal pain, should not be examined after the complete end of menstruation, otherwise the condition will be delayed; 4, Adenomyosis needs to be evaluated during menstruation, and transabdominal ultrasound is mostly preferred for menstrual examinations, and transvaginal ultrasound should be avoided as much as possible to reduce the chance of infection.