MALE INFERTILITY: PREVALENCE, CLINICAL PRESENTATION, AND DIAGNOSTIC STEPS

Infertility is a clinical problem affecting approximately 15 percent of all couples. Despite the common misperception that females are the major cause of conception difficulties, male factor is present in at least half of the cases (1).

The standard evaluation of male infertility includes complete medical history, focused physical examination, laboratory testing (including semen analysis and determination of the hormone profile), and, in certain situations, selective imaging. Male infertility may be caused by abnormalities in the normal development or fertilization capacity of spermatozoa (e.g., vascular, genetic, hormonal, or immunological) or interference in the transport of spermatozoa from the testis to the prostatic urethra (e.g., agenesis or obstruction).

Azospermia is defined as the complete absence of spermatozoa in the ejaculate, and is found in 5 percent of all infertile couples presenting to infertility clinics (2,3). Azospermia from obstructive causes can be categorized as partial or complete. Complete obstruction, accounting for about 1 percent of cases of azospermia, is localized to the epididymis in 30–67 percent and to the testis in 15 percent of cases. Distal ejaculatory duct obstruction occurs in only 1–3 percent of patients with obstructive azospermia (4). However, partial obstruction of the ejaculatory tract accounts for another 5 percent of male factor infertility (5). Functional obstruction of the distal seminal ducts, which is hypothesized to be related to local neuropathy, has also been reported (6).