Azoospermia may be due to hypothalamic-pituitary failure, primary testicular failure (nonobstructive azoospermia) or obstruction of the genital tract (obstructive azoospermia).
Hypogonadotrophic hypogonadism, which is a condition caused by hypothalamic or pituitary dysfunction, accounts for less than 1% of male factor fertility problems.
It results in a deficiency of LH and FSH, which is associated with failure of spermatogenesis and testosterone secretion.
Primary testicular failure is the most common cause of male infertility due to oligozoospermia and is the cause of nonobstructive azoospermia.
Testicular failure may be due to cryptorchidism, torsion, trauma, orchitis, chromosome disorders (Klinefelter’s syndrome, Y-chromosome microdeletions), systemic disease, radiotherapy or chemotherapy; however, in the majority of cases (66%) the cause is unknown.
The diagnosis is based on reduction in testicular size and elevation of serum FSH levels.
There is no effective treatment to restore fertility in primary testicular failure.
Obstructive azoospermia is uncommon with a prevalence of less than 2%.
The diagnosis is based on normal testis size and normal serum FSH levels. This includes conditions such as congenital bilateral absence of vas deferens (CBAVD). CBAVD is commonly associated with cystic fibrosis mutations or renal tract abnormality (e.g. an absent kidney).
Anejaculation and Retroejaculation
Anejaculation is defined as the total failure of seminal emission into the posterior urethra.
Retrograde ejaculation is the substantial propulsion of seminal fluid from the posterior urethra into the bladder.
Anejaculation is a relatively uncommon occurrence in the general population, and retrograde ejaculation accounts for about 0.3–2.0% of male fertility problems.
Anejaculation and retrograde ejaculation may result from spinal cord injury, transurethral prostatectomy, retroperitoneal lymph node dissection, diabetes mellitus, transverse myelitis, multiple sclerosis or psychogenic (idiopathic) disorders.
With the advent of ICSI, since only a small number of motile spermatozoa is required for a successful fertilisation, both ejaculation disorders can be considered as treatable conditions.
Men undergoingtreatments that cause infertility should be offered the opportunity to cryopreserve semen.