The investigators hypothesize that infertility patients undergoing IUI who receive female autologous platelet-rich plasma (PRP) co-incubation with husband's sperm would have higher clinical pregnancy rate.

Primary outcome:

To compare the incidence of clinical pregnancy outcome in those infertility patients undergoing IUI with female PRP co-incubation with husband's sperm group and non-PRP group.

Secondary outcomes:

• To evaluate the post-culture sperm parameters between the intervention group and control group
• To evaluate the IUI parameter between the intervention group and control group
• To evaluate the safeness between the female PRP co-incubation with husband's sperm in the IUI group and non-PRP group, including potential infection rate or other pregnancy outcomes such as miscarriage, multiple pregnancy, ectopic pregnancy and molar pregnancy

Inclusion Criteria:

• Patients who were eligible for IUI cycles in Assissted Reproduction Technolog unit, Prince of Wales Hospital
• Female patients aged >18 years old and < 42 years old
• BMI < 30 kg/m2

Exclusion Criteria:

• Concurrent administration of other agents such as prednisolone, intravenous immunoglobulin, or G-CSF
• Administration of anticoagulants or NSAIDs at least 7 days before PRP infuse
• Drug addiction
• Untreated urinary tract infection
• Underlying uncontrolled diabetes or hypertension, chromosomal or uterine abnormalities, genetic, hematologic, immunological, or endocrine disorders
• Chronic disease, systemic disease or cancers
• Blood diseases (sepsis, thrombocytopenia)
• Poor sperm samples (raw sample TMS <5 x 106)
• Smoking and drinking alcoholic beverages on the day of IUI
• Fever on the day of IUI
• Redduse or incomplete in obtaining informed consent