It is relatively simple to identify the cause of infertility in women with ovulatory disorders or tubal disease, and in men with semen abnormalities. These categories account for the source of infertility in approximately 75 percent of couples. Infertility in the remaining 25 percent of couples is due to endometriosis (8 percent) or miscellaneous factors (eg, cervical factor, immunological factor, uterine synechiae) (2 percent) or is unexplained (15 percent) [1-3].
Management of couples with unexplained infertility will be reviewed here. Diagnosis and treatment of known causes of infertility are discussed separately. (See "Overview of infertility" and "Pathogenesis and treatment of infertility in women with endometriosis" and "Evaluation of male infertility" and "Treatment of male infertility".)
DEFINITION AND DIAGNOSIS
Unexplained infertility refers to the absence of a definable cause for a couple's failure to achieve pregnancy after 12 months of attempting conception despite a thorough evaluation, or after six months in women 35 and older [4,5]. Authorities vary in their concept of what constitutes a thorough evaluation, and these opinions have evolved over time. Currently, a thorough evaluation typically includes documentation of: