INTRODUCTION

Infertility in a couple is defined as the inability to achieve conception despite one year of frequent unprotected intercourse. Use of this time period, while arbitrary, was based upon a study of 5574 English and American women engaging in unprotected coitus who ultimately conceived between 1946 and 1956 [1]. Among these women, 50 percent conceived within three months, 72 percent within six months, and 85 percent within 12 months. Similar estimates were reported in later studies (figure 1).

There are four main causes of male infertility (table 1):

• Hypothalamic/pituitary disease (secondary hypogonadism) – 1 to 2 percent
• Testicular disease (primary spermatogenesis failure and hypogonadism) – 30 to 40 percent
• Posttesticular defects (disorders of sperm transport) – 10 to 20 percent
• Nonclassifiable – 40 to 50 percent

The noted frequencies represent an estimate of the approximate proportion of patients in each category presenting to a tertiary referral center with capabilities to diagnose subtle defects including Y chromosome microdeletions [2]. It is likely that some of the non-classifiable causes will be genetic or epigenetic defects that have not yet been identified. (See "Causes of male infertility".)

This topic will review the treatment of the different causes of male infertility. The current methods of therapy are divided arbitrarily into the following categories: no available treatment, specific treatment, treatment of uncertain efficacy, empirical treatment, and treatment by assisted reproductive techniques [2-4]. The diagnostic approach to the infertile male is discussed separately. (See "Evaluation of male infertility".)