Diagnostic Evaluation and Treatment of Reduced Arousal and Semen Volume

Initial Diagnostic Evaluation

• The American Urological Association recommends palpating bilaterally for vas deferens to rule out congenital bilateral absence of vas deferens (CBAVD) 1
• Assessing testicular size and consistency is crucial, as normal-sized testes suggest obstruction while atrophic testes indicate spermatogenic failure 1
• Examining for palpable varicoceles is essential, as treatment of clinical (palpable) varicoceles improves semen parameters 1
• Performing digital rectal examination to assess prostate size and consistency is necessary 1
• Checking semen pH is vital, as acidic semen (pH <7.0) with low volume strongly suggests ejaculatory duct obstruction or CBAVD 1
• Measuring serum testosterone and FSH is critical, as low testosterone with low/normal FSH indicates hypogonadotropic hypogonadism, while elevated FSH (>7.6 IU/L) suggests primary testicular failure 1
• Performing post-ejaculatory urinalysis when volume <1 mL (except in bilateral vasal agenesis or hypogonadism) is necessary to diagnose retrograde ejaculation 1

Specific Causes of Reduced Semen Volume

• Finasteride 5 mg/day is associated with reduced semen volume, but 1 mg/day data are inconclusive 2
• Alcohol consumption results in slightly lower semen volume and slightly poorer sperm morphology 2
• Occupational exposure to oil and natural gas extraction reduces semen volume and sperm motility 2
• Poor diet results in reduced fertility 2
• Smoking is associated with slightly reduced fertility 2
• Anabolic steroid use is associated with reduced fertility and should be discontinued 2

Structural Causes

• Ejaculatory duct obstruction (EDO) presents with acidic, azoospermic semen with volume <1.4 mL, normal serum testosterone, and palpable vas deferens 3
• Congenital bilateral absence of vas deferens requires no medical or surgical treatment to restore ejaculatory volume; proceed directly to sperm retrieval (TESE/MESA) with ICSI for fertility 1

Imaging When Indicated

• TRUS or pelvic MRI is indicated for suspected ejaculatory duct obstruction when semen is acidic, volume <1.4 mL, with azoospermia or severe oligospermia with very low motility, normal testosterone, and palpable vas deferens 1
• Do not routinely order TRUS or pelvic MRI as part of initial evaluation—reserve for cases with clear clinical suspicion of EDO 1
• Avoid routine scrotal ultrasound for varicocele diagnosis, as only palpable varicoceles warrant treatment 1

Treatment Based on Etiology

• 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
• Varicocelectomy improves semen parameters and may restore sperm in ejaculate for men with azoospermia, particularly those with hypospermatogenesis on histology 1
• Treatment is indicated for palpable varicoceles with abnormal semen parameters 1
• Subclinical (non-palpable) varicoceles should not be treated, as this does not improve semen parameters or fertility rates 1
• Normalizing serum testosterone levels in patients with delayed ejaculation and testosterone deficiency is essential 4
• Reviewing and modifying medications that may contribute to delayed ejaculation or reduced arousal is crucial 5
• Considering replacement, dose adjustment, or staged cessation of medications contributing to sexual dysfunction is necessary 5
• Referring to a mental health professional with expertise in sexual health for men with lifelong or acquired delayed ejaculation is recommended 5
• Advising modifying sexual positions or practices to increase arousal, as behavioral interventions are a low-risk option that may help enhance arousal and trigger orgasmic response, is essential 5
• Incorporating alternative sexual practices, scripts, and/or sexual enhancement devices to increase physical and psychological arousal is necessary 5
• Using pseudoephedrine, ephedrine, midodrine, bethanecol, yohimbine, cabergoline, or imipramine may be considered for pharmacotherapy of delayed ejaculation 1, 5, 6, 7

Genetic Testing Before Assisted Reproduction

• Karyotype testing is mandatory for azoospermia or severe oligospermia (<5 million/mL) 1
• Y-chromosome microdeletion analysis is required for azoospermia or sperm concentration <1 million/mL 1
• CFTR gene testing for the female partner is mandatory before proceeding with assisted reproduction in cases of CBAVD 1
• Genetic counseling should precede ICSI, as genetic abnormalities may be transmitted to offspring 1

Critical Pitfalls to Avoid

• Never initiate testosterone replacement therapy in men desiring fertility, as it suppresses spermatogenesis 7
• Do not use ultrasound to hunt for subclinical varicoceles—only palpable varicoceles benefit from treatment 1
• Do not delay genetic testing—results impact counseling and treatment decisions before proceeding with assisted reproduction 1
• Stress is associated with reduced sperm progressive motility but has no association with semen volume, so do not attribute low semen volume to stress alone 2