Role of assisted reproduction techniques in the management of unexplained male infertility

Abstract

The inability of healthcare provider to conclusively identify the cause of infertility in couples leads to the designation of unexplained infertility. It is likely that abnormalities leading to infertility exists in couples but not detected by the current methods and the state of technology. Normal semen parameters in men reduce but do not completely eliminate the probability of male infertility. The wide range in World Health Organization (WHO) reference values of semen parameters, repeated revisions of normal reference range over the years, significant variation in interlaboratory assessment of sperm characteristics, and use of different analytical criteria (WHO versus Krueger’s Strict morphology) further complicates the clinical assessment of normal semen parameters. High incidence of chromosomal aberrations and/or high percentage of DNA damage in sperm, oxidative stress, exposure of men to environmental pollutants/toxins, etc. may be likely factors that can be the suspected cause of unexplained infertility. Abnormal expression of certain sperm proteins may play a role in failure of fertilization resulting in unexplained male infertility at clinical level. Unexplained male infertility is strongly suspected in couples if the female partner presents with the history of successful pregnancy in not too distant past and subsequent comprehensive diagnostic tests fail to lead to a confirmed infertility diagnosis. In the absence of any apparent treatable condition, the treatment is largely empiric and involves intrauterine insemination (IUI), ovulation induction (OI), and in vitro fertilization (IVF). IVF with intracytoplasmic sperm injection (ICSI) offers couples with unexplained infertility, chance of successful pregnancy while avoiding the probability of fertilization failure. Treatment of men with the suspicion of unexplained male infertility is again empiric and involves prescribing supplements such as L-carnitine, vitamin C, D3, E, folic acid, zinc, selenium, and coenzyme Q10. The efficacy of nutritional supplements in improving male fertility remains to be conclusively documented.