Causes of infertility in men can be explained by deficiencies in sperm formation, concentration, or transportation. This general division allows an appropriate workup of potential underlying causes of infertility and helps define a course of action for treatment.

Signs and symptoms

The initial step in the evaluation of an infertile male is to obtain a thorough medical and urologic history. Such a history should include consideration of the following:

• Duration of infertility
• Previous fertility in the patient and the partner
• Timing of puberty (early, normal, or delayed)
• Childhood urologic disorders or surgical procedures
• Current or recent acute or chronic medical illnesses
• Sexual history
• Testicular cancer and its treatment
• Social history (eg, smoking and alcohol use)
• Medications
• Family history
• Respiratory disease
• Environmental or occupational exposure
• Spinal cord injury

The physical examination should include a thorough inspection of the following:

• Testicles (for bilateral presence, size, consistency, symmetry)
• Epididymis (for presence bilaterally, as well as any induration, cystic changes, enlargement, tenderness)
• Vas deferens (for presence bilaterally, defects, segmental dysplasia, induration, nodularity, swelling)
• Spermatic cord (for varicocele)
• Penis (for anatomic abnormalities, strictures, or plaques)
• Rectum (for abnormalities of the prostate or seminal vesicles)
• Body habitus

Depending on the findings from the history, detailed examination of other body functions may also be warranted.

Diagnosis

The semen analysis is the cornerstone of the male infertility workup and includes assessment of the following:

• Semen volume (normal, 1.5-5 mL)
• Semen quality
• Sperm density (normal, >15 million sperm/mL)
• Total sperm motility (normal, >40% of sperm having normal movement)
• Sperm morphology (sample lower limit for percentage of normal sperm is 4%)
• Signs of infection – An increased number of white blood cells (WBCs) in the semen may be observed in patients with infectious or inflammatory processes
• Other variables (eg, levels of zinc, citric acid, acid phosphatase, or alpha-glucosidase)

Other laboratory tests that may be helpful include the following:

• Antisperm antibody test
• Hormonal analysis (FSH, LH, TSH, testosterone, prolactin)
• Genetic testing (karyotype, CFTR, AZF deletions if severe oligospermia (<5 million sperm/mL)

Imaging studies employed in this setting may include the following:

• Transrectal ultrasonography
• Scrotal ultrasonography
• Vasography

An abnormal postcoital test result is observed in 10% of infertile couples. Indications for performing a postcoital test include semen hyperviscosity, increased or decreased semen volume with good sperm density, or unexplained infertility.

If the test result is normal, consider sperm function tests, such as the following:

• Capacitation assay
• Acrosome reaction assay
• Sperm penetration assay
• Hypoosmotic swelling test
• Inhibin B level
• Vitality stains

Testicular biopsy is indicated in azoospermic men with a normal-sized testis and normal findings on hormonal studies to evaluate for ductal obstruction, to further evaluate idiopathic infertility, and to retrieve sperm. 

Management

The following causes of infertility, if identified, can often be treated by medical means:

• Endocrinopathies
• Antisperm antibodies
• Retrograde ejaculation
• Poor semen quality or number
• Lifestyle issues
• Infections

• Varicocelectomy
• Vasovasostomy or vasoepididymostomy
• Transurethral resection of the ejaculatory ducts
• Sperm retrieval techniques
• Electroejaculation
• Artificial insemination
• Assisted reproduction techniques
• In vitro fertilization
• Gamete intrafallopian transfer (GIFT) and zygote intrafallopian transfer (ZIFT)
• Intracytoplasmic sperm injection