Purpose of review: This paper reviews the investigation of male subfertility and the current consensus on its management.
Recent findings: Management of the subfertile man is mainly authority based. Few randomized trials have been published in this field because of the inherent difficulties involved in studying male subfertility.
Summary: To date, few randomized controlled trials with pregnancy as the main outcome measure have been published. Evidence-based guidelines are therefore limited and clinical practice is merely dominated by authority-based guidelines. More studies are needed to evaluate the treatment of male subfertility in certain subgroups of men. When specific treatments are not indicated or have failed, intrauterine insemination may be considered as the first-line approach. If after three to six cycles of intrauterine insemination no pregnancy is obtained, optimized in-vitro fertilization is to be considered when dealing with long-standing infertility in a couple with a normal fertility status in the female partner. The choice between in-vitro fertilization and intracytoplasmic sperm injection is difficult because of the lack of good randomized controlled trials in moderate male subfertility. When less than 0.5 x 10 progressively motile spermatozoa are available after preparation, intracytoplasmic sperm injection may be the treatment of choice.