What is hysterosalpingography Hysterosalpingography (HSG) is performed by injecting contrast into the uterine cavity and the fallopian tubes through a catheter, and then fluoroscopy and radiographs are taken under X-ray. The test is less invasive and can make a more correct diagnosis of tubal obstruction with an accuracy rate of 80% and has certain therapeutic effects. Indications for hysterosalpingography 1. To understand whether the fallopian tubes are patent, their morphology and obstruction site. 2.To understand the morphology of the uterine cavity, to determine the presence of uterine malformations and types, the presence of uterine adhesions, submucosal fibroids, endometrial polyps and foreign bodies, etc. 3.Inactive stage of internal genital tuberculosis. 4. For unexplained habitual miscarriage, an imaging should be done after ovulation to find out whether the endocervix is loose and whether the cervix and uterus are deformed. Pre-operative preparation 1. 3 to 7 days after menstruation and 3 days before the procedure, no sexual intercourse; 2. iodine allergy test, negative before the procedure; 3. half an hour before the procedure, intramuscular injection of atropine 0.5mg to relieve spasm; 4. empty the bladder before the procedure, and perform clean enema before the procedure for constipation to keep the uterus in normal position and avoid external pressure artifact.