This study evaluates the difference of imaging diagnostic quality and fertility promoting effect in the diagnosis and treatment of infertility by hysterosalpingography between using ethiodized poppyseed oil and the second-generation non-ionic monomer contrast. Half of participants will receive ethiodized poppyseed oil for hysterosalpingography, while the other half will receive the second-generation non-ionic monomer contrast for hysterosalpingography.

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.

It is not yet known if there will be a plan to make IPD available.