Couples with unexplained infertility who go to a fertility center for treatment are often advised to undergo intrauterine insemination (IUI). In the absence of known tubal pathology and severe oligohydramnios in the male partner, IUI (especially using ovulation promotion methods) is often seen as the treatment of choice. Compared to in vitro fertilization treatment (IVF/ICSI), IUI is easy to perform, less medicated, less expensive, less painful for the patient, and more in line with the fertilization process in the human physiological condition. However, if patients are not screened, the expected success rate of IUI is significantly lower than IVF, and for this reason alone, many patients prefer to spend money and suffer rather than opt for IUI treatment. In fact, if the right group of patients is carefully screened, the expected clinical pregnancy rate per cycle for IUI can be as high as 40%, which is not significantly lower than that of IVF/ICSI. How do you screen the right group for IUI? The following criteria may be helpful: female partner < 38 years of age female partner has no history of tubal pathology or negative tubal patency test (normal) male partner has normal routine semen (3 days of abstinence semen specimen, two consecutive examinations) or has at least 5 million forward moving sperm per ejaculation confirmed by simulated sperm retrieval test despite the presence of oligospermia male partner has sperm morphology with aberrant sperm rate < 85% male partner Normal seminal plasma anti-sperm antibodies (AsAb) Normal female blood AsAb Normal post-coital test (PCT) results