Necrozoospermia

Necrozoospermia is a high proportion of dead sperm in the ejaculate, shown by vitality under the lower reference limit of 54%. Motility is low or absent, and the immotile sperm are non-viable. It is uncommon, and found in less than 1 to 2% of infertile men.

It is separated from asthenozoospermia with viable but immotile sperm, where the defect lies in the flagellum. The causes and treatments differ.

Pathophysiology. Sperm die when exposed to damage in the testis, epididymis or accessory glands.

Causes:

• Genital tract infection and inflammation (prostatitis, epididymitis, seminal vesiculitis), with leucocytes and oxidative stress.
• Partial epididymal or ejaculatory duct obstruction with prolonged storage and sperm ageing.
• Long abstinence, varicocele, heat, and febrile illness.
• Spinal cord injury and neurological disease.
• Testicular cancer, chemotherapy and radiotherapy, and antisperm antibodies.
• Genetic causes (rare).
• Idiopathic.

Infertility with usually no symptoms. There may be a history of genital infection, prolonged abstinence, spinal injury or testicular disease. Look for epididymal fullness, prostatic tenderness, varicocele and testicular masses.

• Semen analysis with vitality: eosin nigrosin stain (dead sperm stain pink or red) or hypo-osmotic swelling test (viable sperm have swollen, coiled tails). Repeat on a second sample after 2 to 3 days of abstinence.
• Semen culture, leucocyte count, and urine nucleic acid test for chlamydia, gonorrhoea and mycoplasma.
• Hormones: FSH, LH, total testosterone, prolactin.
• Scrotal ultrasound for varicocele, epididymal changes and masses. Transrectal ultrasound for ejaculatory duct obstruction.
• Antisperm antibody test, and DNA fragmentation testing.
• Testicular biopsy findings, when retrieval is planned, show the origin of the problem.

Differential diagnosis.

• Asthenozoospermia with viable immotile sperm (flagellar defect)
• Nonobstructive azoospermia with dead sperm in a diluted sample
• Partial obstruction
• Leucocytospermia
• Artefact from delayed analysis or poor stain
• Testicular cancer

• Treat infection: doxycycline 100 mg orally twice daily for 14 days for chlamydia and mycoplasma, or ciprofloxacin 500 mg orally twice daily for 14 days or longer for prostatitis, with the dose reduced when eGFR is under 50. Treat partners.
• Frequent ejaculation (daily or every second day for 1 to 2 weeks) shortens epididymal storage and may improve vitality.
• Varicocelectomy for a palpable varicocele with abnormal semen and couple infertility.
• Antioxidants have inconsistent evidence. If used, coenzyme Q10 200 to 300 mg daily for 3 to 6 months.
• Assisted reproduction:
  • Intrauterine insemination is not useful when most sperm are dead.
  • In vitro fertilisation with intracytoplasmic sperm injection using viable sperm, selected by hypo-osmotic swelling, laser, or pentoxifylline stimulated motility. Ejaculated sperm are poorly viable.
  • Testicular sperm extraction or aspiration, which gives a higher proportion of live sperm and better fertilisation and pregnancy rates than ejaculated sperm in severe necrozoospermia.
• Treat the underlying cause: reconstruct obstruction when possible, manage spinal cord injury with electroejaculation or vibratory stimulation and early sperm banking.
• Cryopreserve sperm before gonadotoxic treatment.

Monitoring. Repeat semen analysis and vitality at 3 months after treatment. Review the couple at 6 months.

Referral and escalation. Refer to urology or andrology and a fertility unit. Urgent referral for a testicular mass or fever with scrotal pain.