What is the appropriate workup for a patient presenting with decreased ejaculate?

Workup for Decreased Ejaculate Volume

The appropriate workup for a patient presenting with decreased ejaculate volume should begin with semen analysis, followed by targeted testing based on volume and other parameters to identify the underlying cause, which may include retrograde ejaculation, ejaculatory duct obstruction, or hormonal abnormalities. 1

Initial Evaluation

History

• Sexual and reproductive history
• Duration of the problem (lifelong vs. acquired)
• Medication use (particularly those with antiadrenergic effects)
• Previous surgeries (especially pelvic, prostate, or retroperitoneal)
• Symptoms of endocrinopathy
• History of diabetes, neurological disorders, or pelvic trauma
• Presence of other sexual dysfunction

Physical Examination

• Focused genital examination including:
  • Examination of the penis and urethral meatus
  • Measurement and palpation of the testes
  • Assessment for presence and consistency of vas deferens and epididymides
  • Evaluation for varicocele
  • Secondary sex characteristics
  • Digital rectal examination 1

Diagnostic Testing Algorithm

Step 1: Semen Analysis (Two Samples)

• Collect after 2-3 days of abstinence
• Keep at body temperature and analyze within 1 hour
• Normal parameters:
  • Volume: 1.5-5.0 mL
  • pH: >7.2
  • Sperm concentration: >20 million/mL 1

Step 2: If Volume <1.4 mL

• Check pH:
  • If pH <7.0 (acidic): Suggests distal genital tract obstruction 1, 2
  • If pH >7.0: Consider other causes

Step 3: Post-Ejaculatory Urinalysis

• Indicated when ejaculate volume is <1 mL (except in patients with bilateral vasal agenesis or hypogonadism)
• Presence of sperm in post-ejaculatory urine confirms retrograde ejaculation 1, 3

Step 4: Hormonal Evaluation

• Indicated if:
  • Semen analysis is abnormal (especially if concentration <10 million/mL)
  • Sexual function is impaired
  • Clinical findings suggest endocrinopathy
• Minimum testing:
  • Serum testosterone
  • Follicle-stimulating hormone (FSH) 1
  • Consider prolactin if clinically indicated 1

Step 5: Imaging Studies

• Transrectal ultrasonography (TRUS):

  • Indicated in patients with:
    • Azoospermia with palpable vas deferens and low ejaculate volume
    • Acidic, azoospermic semen with volume <1.4 mL
    • Normal testosterone and palpable vas deferens 1
  • Can identify ejaculatory duct obstruction, seminal vesicle abnormalities

• Pelvic MRI:

  • Consider if TRUS is negative or inconclusive
  • Better characterizes prostate cysts and ejaculatory duct abnormalities 1, 2

• Scrotal ultrasound:

  • Indicated when physical examination of scrotum is difficult or inadequate
  • When testicular mass is suspected 1

Special Considerations

Genetic Testing

• Consider karyotype testing for males with:

  • Primary infertility and azoospermia
  • Sperm concentration <5 million/mL with elevated FSH
  • Testicular atrophy
  • Impaired sperm production 1

• Y-chromosome microdeletion testing:

  • For azoospermic males with suspected impaired sperm production
  • For severely oligospermic males with sperm concentration <5 million/mL 1

• Cystic fibrosis mutation testing:

  • For men with congenital bilateral absence of vas deferens (CBAVD)
  • Should include testing of female partner before proceeding with treatment using sperm from men with CBAVD 1, 2

Common Causes of Decreased Ejaculate Volume

1. Retrograde ejaculation - Prevalence of 40.5% in patients with hypospermia 3

   • Confirmed by finding sperm in post-ejaculatory urine

2. Ejaculatory duct obstruction

   • Characterized by low volume, acidic pH, and azoospermia or severe oligospermia 1, 2

3. Hypogonadism

   • Associated with hormonal abnormalities and other signs of testosterone deficiency

4. Congenital bilateral absence of vas deferens

   • Can be diagnosed by physical examination 1

5. Ejaculatory dysfunction

   • May require specialized treatment approaches 1

Pitfalls to Avoid

• Collection errors: Ensure proper collection technique and timing (partial sample collection is a common cause of artifactual low volume) 4

• Inadequate abstinence period: Can affect volume and other parameters; standardize to 2-3 days 1

• Overlooking medications: Many medications, particularly those with antiadrenergic effects, can cause ejaculatory dysfunction 5

• Missing retrograde ejaculation: Always perform post-ejaculatory urinalysis when volume is low 1

• Premature treatment: Complete the diagnostic workup before initiating treatment 1

By following this systematic approach, the underlying cause of decreased ejaculate volume can be identified, allowing for appropriate management to improve fertility outcomes and quality of life.