RCT of Ethiodized Poppyseed Oil VS the Second-generation Non-ionic Monomer Contrast in Hysterosalpingography of Infertile Patients.

Inclusion Criteria: * Aged between 21 to 39 years, Female; * Had spontaneous menstrual cycle; * Had been trying to conceive for at least 1 year; * There was an indication for evaluation of tubal patency by means of hysterosalpingography. * Understand and sign informed consent. Exclusion Criteria: * Known endocrine disorders(e.g., the polycystic ovary syndrome, diabetes, hyperthyroidism, and hyperprolactinemia); * Less than eight menstrual cycles per year; * A high risk of tubal disease (as indicated by a history of pelvic inflammatory disease, previous chlamydia infection, or known endometriosis); * Hyperthyroidism; * Vaginitis, acute or subacute pelvic inflammatory active phase, uterus or fallopian tube tuberculosis; * Uterine or cervical bleeding; * Menelipsis without excluding pregnancy; * Severe heart disease and lung disease; * Body temperature beyond 37.5 ℃ within 3 days before hysterosalpingography; * A total motile sperm count of \<1 million sperm per milliliter; * Complications or social environment that can cause patients to fail to follow the study plan and even endanger the patient's safety.