Unexplained infertility: an update and review of practice.

Of the couples unable to conceive without any identifiable cause, 30% are defined as having unexplained infertility. Management depends on duration of infertility and age of female partner. This review describes and comments on the definition and evidence for the management of unexplained infertility. A literature search was conducted in EMBASE, Medline, Ovid and Cochrane Database of Systematic reviews using the terms 'infertility', 'unexplained infertility', 'idiopathic infertility', 'definition of infertility', 'treatment options', 'intrauterine insemination', 'ovulation induction', 'Fallopian tube sperm', 'GIFT' and 'IVF'. There is no uniform definition for unexplained infertility. This varies in the literature depending on the duration of infertility and the age of the female partner. The treatment of unexplained infertility is empirical and many different regimens have been used. Among these are expectant management, ovulation stimulation with clomiphene citrate, gonadotrophins and aromatase inhibitors, Fallopian tube sperm perfusion, tubal flushing, intrauterine insemination, gamete intra-Fallopian transfer and IVF. The standard protocol is to progress from low-technology to high-technology treatment options. On the best available evidence, an algorithm for management is suggested. There is a definite need for multicentre randomized controlled trials to identify the best treatment option in unexplained infertility using a standard definition.