OLIGOSPERMIA AZOOSPERMIA

Oligospermia and azoospermia
Oligospermia
Defined as a sperm concentration of less than 20 million/ml of ejaculate.

Aetiology
Varicoceles; idiopathic; androgen deficiency. It is identified in ~60% of patients presenting with testicular cancer or lymphoma.

Associated disorders
It is often associated with abnormalities of morphology and motility. The combined disorder is called oligoasthenoteratospermia (OAT) syndrome. Common causes include varicoceles; cryptorchidism; idiopathic; drug and toxin exposure; febrile illness.
Investigations Semen analysis: sperm counts <5-10 million/ml (severe form) require hormone investigation, including FSH and testosterone. Severe oligospermia is associated with seminiferous tubular failure, small soft testes, and ↑ FSH.

Treatment
Correct the underlying cause. Idiopathic cases may respond to empirical medical therapy (clomiphene) or require assisted reproductive techniques.

Azoospermia
Defined as an absence of sperm in the ejaculate fluid.

Aetiology
- Obstructive Absent or obstructed vas deferens; epididymal or ejaculatory duct obstruction (related to infection, cystic fibrosis).
- Non-obstructive Hypogonadotrophism (Kallmann's syndrome, pituitary tumour); abnormalities of spermatogenesis (chromosomal anomalies, toxins, idiopathic, varicocele, orchitis, testicular torsion).

Investigations
- Hormone assay (raised FSH indicates non-obstructive cause; normal FSH with normal testes indicates increased likelihood of obstruction).
- Chromosomal analysis may be used to exclude Kleinfelter's syndrome in patients presenting with azoospermia, small soft testes, gynaecomastia, ↑ FSH/LH and ↓ testosterone.
- Testicular biopsy is performed to assess if normal sperm maturation is occurring, and for sperm retrieval (for later therapeutic use).
- Transrectal ultrasound scan assesses absence or blockage of vas deferens, and ejaculatory duct obstruction. Exclude cystic fibrosis in patients with vas deferens defects.

Management
Treatment will depend on underlying aetiology.
- Bilateral absence or agenesis of vas deferens Microsurgical epididymal sperm aspiration (MESA), or consider artificial insemination using donor (AID).
- Primary testicular failure with testicular atrophy Testicular sperm extraction (TESE); in vitro fertilization (IVF); or consider AID.
- Primary testicular failure with normal testis TESE; IVF; AID.
- Obstructive cause with normal testis Epididymovasostomy; vasovasostomy.