Unexplained infertility usually refers to a diagnosis (or lack of diagnosis) made in couples in whom all the standard investigations such as tests of ovulation, tubal patency and semen analysis are normal.

Incidence 10-30% (ASRM 2006)

For the infertile couple, a ‘diagnosis’ of unexplained infertility may be very frustrating and is often interpreted by them as meaning that if there is no explanation for the cause of infertility, there is, therefore, no effective treatment.

The basic evaluation should provide evidence of ovulation, adequate sperm production and patency of fallopian tubes.{asrm2006}

The prognosis is worse when the duration of infertility exceeds 3 years and the female partner is >35 years of age (Collins et al.,1995).

Prognostic factors related to a higher cumulative pregnancy rate are duration of infertility less than 2 years, a previous pregnancy in the same relationship and female age <30 years.