Unexplained infertility: prevalence, possible causes and treatment options. A review of the literature

The diagnosis of unexplained infertility established when all the standard infertility investigations are normal, including tubal patency (hysterosalpingogram and/or laparoscopy), normal ovulatory function (basal body temperature, cervical mucus changes, serum luteinizing hormone surge or mid-luteal progesterone), and normal semen analysis. The prognosis of unexplained infertility is good without therapy in women < 35 years and when the duration of infertility is < 2 years. Clomiphene citrate did not show any advantage over placebo in the treatment of unexplained infertility. The role of intrauterine insemination in treatment of unexplained infertility still raises many questions, particularly regarding its superiority in un-stimulated cycles over stimulated cycles or timed intercourse. In-vitro fertilization increases the pregnancy rate in women with unexplained infertility, and the present environment is in favor of single embryo transfer to reduce the multiple pregnancy rate. There is no definite answer for the question what is the best management approach for couples with unexplained infertility?