The role of the laboratory in the investigation of infertility.

The incidence and the causes of the various types of infertility in men and women are described. Accurate diagnosis of the cause or causes of a couple's infertility is important as the treatment is often expensive and lengthy. A thorough clinical investigation of the couple will indicate which laboratory tests to embark upon. Endocrine abnormalities may account for about a third of diagnoses in women but are rare in men. Standard immunoassay procedures are used for hormone assays to diagnose endocrinopathies and should be performed in a logical sequence. They help to identify hyperprolactinaemia and to distinguish primary gonadal failure from lesions of the hypothalamic-pituitary axis. The common drugs available for treatment are listed and guidelines are given on management during treatment. Hormone assays are useful, but ultrasonic scanning is efficient and rapid and is becoming the preferred method for monitoring follicular growth.