Azoospermia: Causes, Symptoms, and Treatment
Also known as: Zero sperm count, No sperm in ejaculate
Definition and impact on male fertility
Azoospermia is the complete absence of sperm in the ejaculate, confirmed on two separate semen analyses. It is one of the most severe causes of male infertility, affecting about 1% of men in the general population and 10 to 15% of men evaluated for infertility. In the United States, where infertility affects an estimated 10 to 15% of couples, azoospermia is a common reason for specialized care in urology and reproductive medicine.
Causes and risk factors
Azoospermia falls into two main categories. Obstructive azoospermia results from a blockage in the sperm ducts: congenital bilateral absence of the vas deferens, chronic epididymitis, a history of vasectomy, or prior groin surgery. Non-obstructive azoospermia reflects a failure of sperm production: Klinefelter syndrome (47,XXY), Y chromosome microdeletions, untreated undescended testicle (cryptorchidism), chemotherapy, pelvic radiation, mumps orchitis, or exposure to endocrine disruptors. Some hormonal causes (hypogonadotropic hypogonadism) can be treated directly.
Symptoms
Azoospermia is, in the vast majority of cases, symptom-free: the man has no functional signs, and it is discovered during a couple’s fertility workup. A few situations may point toward the diagnosis beforehand:
- History of gonadotoxic treatment (chemotherapy, radiation therapy)
- Testicular pain or swelling suggesting orchitis or epididymitis
- Very low or absent ejaculate volume (aspermia)
- Breast enlargement (gynecomastia) associated with Klinefelter syndrome
- Absent vas deferens on physical exam
Diagnosis
Diagnosis relies on two abnormal semen analyses confirming the absence of sperm after centrifugation. The additional workup includes hormone testing (FSH, LH, testosterone), a blood karyotype, testing for Y chromosome microdeletions, and a scrotal and transrectal ultrasound. A testicular biopsy can distinguish obstructive from non-obstructive forms and check for pockets of residual sperm production.
Treatments
Treatment depends on the identified cause:
- Obstructive azoospermia: reconstructive surgery of the sperm ducts (vasovasostomy, vasoepididymostomy) can restore flow in favorable cases; otherwise, surgical sperm extraction (MESA, TESE) combined with IVF with ICSI is offered
- Non-obstructive azoospermia from hypogonadotropic hypogonadism: hormone therapy to induce sperm production using gonadotropins (FSH, hCG), often with favorable results
- Other non-obstructive forms: testicular sperm extraction (micro-TESE) combined with ICSI, with variable success rates depending on the underlying tissue findings
- Donor sperm: an option when no sperm can be retrieved
- Preventive sperm banking before any anticipated gonadotoxic treatment
Prevention
Some causes of azoospermia can be prevented or anticipated. Sperm banking is recommended before any chemotherapy, pelvic radiation, or surgery that could affect fertility. Treating cryptorchidism early, before 18 months of age, limits long-term damage to sperm production. Avoiding prolonged scrotal heat exposure, endocrine disruptors, and anabolic steroids also helps preserve sperm quality. Preconception genetic counseling is advised for those with a family history of Klinefelter syndrome or a known chromosomal condition.
When should you see a doctor?
See a doctor if a fertility evaluation after 12 months of unprotected intercourse has not led to pregnancy, or after 6 months if you are over 35 or have a history that could affect fertility (cryptorchidism, chemotherapy, genital infection). An abnormal semen analysis should always be confirmed and evaluated by a urologist or reproductive medicine specialist.
Sources
- StatPearls: Azoospermia, National Center for Biotechnology Information, supports the 1% general-population and 10 to 15% infertile-men figures, the two-specimen definition, the hormonal and genetic workup, and the surgical and hormonal treatment options
- ASRM: Frequently asked questions about infertility, American Society for Reproductive Medicine, supports infertility affecting 10 to 15% of couples and azoospermia as a common male-factor cause
- MedlinePlus: Male infertility, U.S. National Library of Medicine health information
- NICHD: Causes of male infertility, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health
- NICHD: What is infertility?, National Institutes of Health, supports the 12-month and 6-month (over 35) evaluation thresholds
- HealthyChildren.org: Undescended testicles, American Academy of Pediatrics, supports treating cryptorchidism within the first 18 months