Unexplained Infertility, the Controversial Matter in Management of Infertile Couples

30% of infertile couples worldwide are diagnosed with unexplained or idiopathic infertility and the problem is defined as the lack of an obvious cause for a couple's infertility and the females' inability to get pregnant after at least 12 cycles of unprotected intercourse or after six cycles in women above 35 years of age for whom all the standard evaluations are normal. The veracity of 'unexplained infertility' term has been challenged by many clinicians and researchers; they emphasize that the assignment of this title to an infertile couple is much dependent on the quantity, quality and nature of the applied diagnostic tests (1, 2). According to the ESHRE guidelines, necessary tests for unexplained infertility are semen analysis, assessment of ovulation and the luteal phase, and assessment of tubal patency by hysterosalpingogram or laparos-copy. However, there are controversial opinions about the value of endometrial biopsy, ovarian reserve (AMH, AFC), post-coital test and serum prolactin levels. Our inability to find the causes of couples' infertility does not mean that there is no cause for the disorder. Extensive research should be conducted on other possible causes of failed conception such as ovarian and testicular dysfunctions, sperm and oocyte quality, fallopian transport defects, endometrial receptivity, im-plantation failures, and endometriosis (3, 4). Management of infertile couples with idiopathic cause needs individualized treatment. Several key variables including age, infertility history, treatment history, costs, and risks should be considered in selection of the suitable treatment plan. The rate of spontaneous conception in these couples is more than the couples with defined causes of infertility and several studies have reported that the rate of spontaneous pregnancy was 13-15% during the first year of attempt which increased to 35% during the next two years of attempt. Moreover, the rate could reach 80% in younger couples during the following three years of unprotected intercourse without any adjuvant therapy. The rate of spontaneous pregnancy drastically declines with infertility duration of more than 3 years and in women over 30 years of age. There are several mathematical models such as Hunault's prognostic model to estimate the rate of spontaneous pregnancy. Therefore, when the chance of spontaneous conception for a couple is so high, no further fertility treatment is needed and the best plan for them would be expectant management (1, 3, 5). However, the main problem for treatment in these couples is disagreement of physicians on the management of unexplained subfertility. Many …