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3. PRIMARY SPERMATOGENIC FAILURE
3.1 Definition
Primary spermatogenic failure is defined as any spermatogenic alteration originated by causes different from hypothalamic-pituitary diseases.
The
severe forms of primary spermatogenic failure, caused by different
aetiologies, have a clinicalpresentation
as non-obstructive azoospermia.
The
prevalence of azoospermia in the general population has been
estimated at 2% [1]. The incidence at amale
infertility clinic was found to be as high as 10-20% [2,3].
Testicular histology shows different degrees of spermatogenic
alterations, ranging from tubular damage to hypospermatogenesis. Even
in cases of Sertoli cell-only
Syndrome (SCOS), it is possible to find seminiferous tubules with
some degree of spermatogenesis. Depending on the severity of the
process, FSH levels can be elevated and the testes can be reduced in
size and/or
consistency. Before the ICSI era, increased serum FSH was considered
a sign of severe spermatogenic failure,
and no other diagnostic procedures were indicated. It was
demonstrated that ICSI [4] could also be used
to treat some cases of non-obstructive (testicular) azoospermia.
However, about 20% of these cases are associated with chromosomal
abnormalities or genetic translations of the Yq chromosome (see above
Genetic
disorders in infertility).