What are the treatment options for low volume semen (oligozoospermia)?

Treatment of Low Semen Volume

For low semen volume (<1.4 mL), the primary goal is to identify and treat the underlying cause—whether obstructive (ejaculatory duct obstruction, congenital bilateral absence of vas deferens), functional (retrograde ejaculation, hypogonadism), or related to varicocele—rather than treating the symptom itself. 1

Initial Diagnostic Workup

The evaluation must distinguish between different etiologies, as treatment depends entirely on the underlying cause:

Key Physical Examination Findings

• Palpate for vas deferens bilaterally to rule out congenital bilateral absence of vas deferens (CBAVD), which can be diagnosed by physical examination alone 1, 2
• Assess for palpable varicoceles, as treatment of clinical (palpable) varicoceles improves semen parameters and fertility, while non-palpable varicoceles should not be treated 1
• Evaluate testicular size and consistency, as normal-sized testes suggest obstruction while atrophic testes indicate spermatogenic failure 2
• Perform digital rectal examination to assess prostate size and consistency 2

Critical Laboratory Tests

• Check semen pH: acidic semen (pH <7.0) with low volume strongly suggests ejaculatory duct obstruction or CBAVD 1
• Measure serum testosterone and FSH: low testosterone with low/normal FSH indicates hypogonadotropic hypogonadism, while elevated FSH (>7.6 IU/L) suggests primary testicular failure 2, 3
• Post-ejaculatory urinalysis when volume <1 mL (except in bilateral vasal agenesis or hypogonadism) to diagnose retrograde ejaculation 2

Imaging When Indicated

• TRUS or pelvic MRI for suspected ejaculatory duct obstruction: indicated when semen is acidic, volume <1.4 mL, with azoospermia or severe oligospermia with very low motility, normal testosterone, and palpable vas deferens 1
• Avoid routine scrotal ultrasound for varicocele diagnosis, as only palpable varicoceles warrant treatment 1

Treatment Based on Etiology

Ejaculatory Duct Obstruction

• Transurethral resection of ejaculatory ducts (TURED) is the definitive treatment for confirmed EDO on TRUS or MRI showing dilated seminal vesicles and ejaculatory ducts 1
• Confirm diagnosis with imaging before proceeding, as empiric treatment is not recommended 1

Congenital Bilateral Absence of Vas Deferens

• No medical or surgical treatment restores ejaculatory volume 1
• Proceed directly to sperm retrieval (TESE/MESA) with ICSI for fertility 2
• CFTR gene testing for female partner is mandatory before proceeding with assisted reproduction 2

Hypogonadotropic Hypogonadism

• Human chorionic gonadotropin (hCG) therapy normalizes testosterone, sperm concentration, and semen volume 3
• This represents one of the few truly reversible causes of low semen volume with medical therapy 3
• Avoid testosterone replacement therapy, as it suppresses spermatogenesis and worsens fertility 2

Retrograde Ejaculation

• Alpha-adrenergic agonists (pseudoephedrine, imipramine) to increase bladder neck tone 4
• Sperm retrieval from post-ejaculatory urine for assisted reproduction if medical therapy fails 4

Clinical Varicocele

• Varicocelectomy improves semen parameters and may restore sperm in ejaculate for men with azoospermia, particularly those with hypospermatogenesis on histology 5
• Treatment is indicated for palpable varicoceles with abnormal semen parameters 1, 5
• Do not treat subclinical (non-palpable) varicoceles, as this does not improve semen parameters or fertility rates 1, 5
• Improvements take 3-6 months (two spermatogenic cycles) to manifest 5

Idiopathic Oligozoospermia with Low Volume

• Clomiphene citrate 25 mg on alternate days showed superior improvement in sperm concentration and total sperm count compared to daily dosing in normogonadotropic men 6
• However, evidence for empiric medical therapy remains limited, and most guidelines do not strongly endorse this approach 7

Genetic Considerations Before Treatment

• Karyotype testing is mandatory for azoospermia or severe oligospermia (<5 million/mL) 2
• Y-chromosome microdeletion analysis is required for azoospermia or sperm concentration <1 million/mL 1, 2
• Genetic counseling should precede ICSI, as genetic abnormalities may be transmitted to offspring 2

Common Pitfalls to Avoid

• Do not perform TRUS or pelvic MRI as part of initial evaluation—reserve for cases with clear clinical suspicion of EDO (low volume, acidic, azoospermic semen with normal testosterone and palpable vas) 1
• Do not use ultrasound to hunt for subclinical varicoceles—only palpable varicoceles benefit from treatment 1, 5
• Do not assume low volume alone indicates obstruction—hypogonadism and retrograde ejaculation are functional causes that require different management 3
• Do not delay genetic testing—results impact counseling and treatment decisions before proceeding with assisted reproduction 2