AZOOSPERMIA

BY: MARYAM HOSSEINZADEH

Azoospermia is defined as the absence of sperm in the

ejaculate and is identified in 1% of all men and up to 10%

to 15% of infertile males

Aspermia is defined as a complete absence of seminal fluid during orgasm.

The initial diagnosis of azoospermia is made when no

spermatozoa can be detected on high-powered

microscopic Examination of centrifuged seminal fluid on at

Least two occasions.

The WHO Laboratory Manual for The Examination of Human Semen recommends that the seminal fluid be centrifuged for 15 minutes at a centrifugation speed of, preferably, 3000g or greater.

The complete absence of spermatozoa should be confirmed with repeat testing after a long time, because many external factors

(febrile episodes and some therapies) may cause transient azoospermia.

inability of produced spermatozoa to reach the emitted semen: (excretory or Obstructive Azoospermia)

lack of spermatozoa production in the testes:(Secretory or Non-Obstructive Azoospermia)

Azoospermia may result from

or

NOA

OA

In clinical practice both components are sometimes present in a single patient (mixed genesis azoospermia)

Defects in any of the “ducts” involved in the sperm

delivery system such as:

1) epididymis, 2) vas deferens, 3) ampulla of the vas and 4)

ejaculatory duct.

Ductal obstruction

Congenital

Acquired

(you were born with it)

(you were not born with it)

Vasectomy

Infection

Infection can make a scar form in the epididymis

Is the most common

cause

The evaluation of a patient with azoospermia is performed

to determine the etiology of the patient’s condition.

The etiologies for azoospermia fall into three

principal categories:

pre-testicular

Testicular

post-testicular

pre-testicular azoospermia

Endocrin abnormalities that adversely affect

spermatogenesis (secondary testicular failure),are

rare.

pre-testicular azoospermia is due to a hypothalamic or

pituitary abnormality.

Low serum FSH

Low serum testosterone

Hypogonadotropic hypogonadism

Low serum luteinizing hormone(LH

congenital: Kallmann syndrome

Idiopatic

Trauma, Tumor, Infection, Drug

Testicular failure azoospermia

Or non-obstructive is estimated to affect almost 60%

of azoospermic men.

Testicular etiologies (primary testicular failure) involve disorders of spermatogenesis intrinsic to the testes.

While the term testicular failure would seem to indicate a complete absence of spermatogenesis, men with testicular failure actually have either reduced spermatogenesis [hypospermatogenesis].

Patient have maturation arrest at an early or late stage of spermatogenesis, or a complete failure of spermatogenesis (Sertolicell Only syndrome)Elevated serum FSH

normal or low serum testosterone

post-testicular oazoospermia

post-testicular obstruction or retrograde ejaculation are estimated to affect from 40% of azoospermic men.

Post-testicular etiologies of azoospermia are due to either

ejaculatory dysfunction or obstruction of sperm delivery to the urethral meatus. In these cases, spermatogenesis is normal even though the semen lacks spermatozoa.

Intra testicular ducts: Rete testes

Epididymis: Infection, trauma, surgical damage, Young’s syndrome.

Vas deferens: CBAVD, vasectomy, hernia repair

Ejaculatory duct: congenital cysts, infection, trauma, urethral surgery

Anejaculation/Retrograde ejaculatory

Spinal cord injury, multiple sclerosis, Diabetes, Bladder neck surgery, prostatectomy.

The pre-testicular and post-testicular

abnormalities that cause azoospermia are

frequently correctable.

Testicular Disorders are generally irreversible,

With the possible exception of impaired

spermatogenesis Associated with varicoceles.

NOA and OA:Results with IVF/ICSI

childhood illnesses: orchitis or cryptorchidism

genital trauma

prior pelvic/inguinal surgery

infections

gonadotoxin exposure: prior radiation therapy/chemotherapy

current medical therapy

familial history of birth defects

mental retardation

reproductive failure

cystic fibrosis

Diagnosismedical history

testis size and consistency (normal

testis volume greater than 19 ml)

consistency of the epididymies

secondary sex characteristics

presence and consistency of the

vasa deferentia

presence of a varicocele

masses upon digital rectal

examination

physical examination

measurement of serum testosterone level (T)

follicle stimulating hormone level (FSH)

Luteinizing hormone (LH)

hormone level measurements

Absence of the vasa deferentia(vasal agenesis)

Since normal vasa are easily palpable within the scrotum,

the diagnosis of vasal agenesis, either bilateral or unilateral, is made by physical examination.

Imaging studies and surgical exploration are not necessary to confirm the diagnosis, but may be useful for diagnosing abnormalities associated with vasal agenesis.

For example, an abdominal ultrasound should be considered to Rule out renal anomalies.

About 25 percent of men with unilateral vasal agenesis and 10 percent of men with congenital bilateral absence of the vasa deferentia (CBAVD) have unilateral renal agenesis

Evaluation of specific conditions associated with azoospermia

Due to the embryological association between the vasa And Seminal

vesicles, most patients with vasal agenesis Also have seminal vesicle

hypoplasia or agenesis. Since the majority of semen is derived from the

seminal vesicles, almost all patients with CBAVD have low semen volume.

There is a strong association between CBAVD and mutations of the cystic

fibrosis transmembrane conductance Regulator (CFTR) gene.

Approximately 70% of men with CBAVD and no clinical evidence of a

cystic fibrosis have an identifiable abnormality of CFTR gene.

Almost all male patients With Clinical cystic fibrosis have CBAVD

Since It can be assumed that a man with CBAVD harbors a genetic

abnormality in the CFTR gene, it is important to test his partner for CFTR

gene abnormalities prior to performing a treatment that utilizes his sperm

because of the (approximately 4%) risk that she may be a carrier. Ideally,

genetic counseling should be offered both before and after genetic testing

of both partners.

At a minimum, genetic testing for CFTR mutations in the female partner

should be offered before proceeding with treatments that utilize the sperm

of a man with CBAVD. If the female partner tests positive for a CFTR

mutation, the male should be tested as well. If the female partner has a

negative test for CFTR mutations, testing of the male partner is optional.

Recommendations:

Bilateral testicular atrophy

Bilateral testicular atrophy when accompanied by low serum testosterone

levels is often associated with low semen volume.

Bilateral testicular atrophy may be caused by either primary or secondary

testicular failure. The results of the initial endocrine tests are used to

distinguish between these two possibilities.

An elevated serum FSH level associated with either a normal oror

low serum testosterone level is consistent with

primary testicular failure

All patients with these findings should be offered genetic testing

for chromosomal abnormalities and Y-chromosome microdeletions.

A low serum FSH level associated with bilaterally small testes

and a low serum testosterone level is consistent with

hypogonadotropic hypogonadism.

These patients usually have low serum luteinizing hormone

(LH) levels.

Patients with acquired hypogonadotropic hypogonadism

should be evaluated for functioning and non-functioning

pituitary tumors by measurement of serum prolactin and

imaging of the pituitary gland.

vasa deferentia and testes are normal

semen volume and serum FSH

Azoospermia with Normal ejaculate volume

Reproductive system obstructionor

Spermatogenesis abnormalities

Azoospermia with Low semen volume normal sized testes

Ejaculatory dysfunction or

ejaculatory duct obstruction

Ductal obstruction

key factors

In the azoospermic patient, if the semen volume is

normal (>1ml) and alkaline (pH>7.0), and fructose

poseitive, the seminal vesicles are indeed functional

and emptying through patent ejaculatory ducts.

CBAVD and ejaculatory duct obstruction will not be

diagnostic possibilities (normal testes size).

In these cases, either there exists a blockage to sperm

flow closer to the testes (the vas deferens or the

epididymis) or the testes do not produce sperm

(spermatogenic failure).

Patients with normal ejaculate volume

TESTO

Spermatogenic failure: microdeletion

Testicular failure:klinefelter syndrome

HH: Kallmanns’s syndrome

FSH LH DIAGNOSIS

Patients with normal ejaculate volumesuggestive of NOA (small, soft testes)

In order to distinguish between obstructive and nonobstructive

causes of azoospermia, diagnostic testicular biopsy is indicated

for patients with normal testicular size, at least one palpable vas

deferens and a normal serum FSH level.

Recommendations:

The serum FSH of a patient with normal semen volume is a critical factor in determining whether a diagnostic testicular biopsy is needed to establish the presence or absence of normal spermatogenesis.

Marked elevation of serum FSH (greater than two times the upper Limit of normal) is diagnostic of abnormal spermatogenesis.diagnostic testicular biopsy is not necessary in these patients

If the testicular biopsy is normal

Obstruction at some level in the reproductive system must be present

Most men with obstructive azoospermia and no history suggesting vasal injury have bilateral epididymal

obstruction

Epididymal obstruction can be identified only by surgical exploration.Vasography may be utilized to determine whether there is an obstruction in the vas deferens or ejaculatory ducts.

Patients with low ejaculate volume

Low ejaculate volume (< 1.0 ml), low-pH caused by:

CBAVD (the seminal vesicles are either absent or aplastic)

or

Bilateral ejaculatory duct obstruction (EDO). (the seminal vesicles are normal but cannot deliver their contents)

Seminal pH and fructose

seminal parameters that can be helpful in determining the presence of EDO are

Semen specimens consist only of prostatic fluid

Transrectal ultrasonography (TRUS) is indicated for the diagnosis of EDO in men with low ejaculate volume.

midline cysts, Dilated ED and/or dilated seminal vesicles (greater

than 1.5 cm in anteroposterior Diameter) on TRUS is suggestive,

but not diagnostic of ejaculatory duct obstruction.

Normal seminal vesicle size does not completely rule out the possibility of

obstruction. Therefore, seminal vesicle aspiration (SVA) and seminal

vesiculography may be performed under TRUS guidance to make a more

definitive diagnosis of EDO

The presence of large numbers of sperm in the seminal vesicle of an azoospermic patient is highly suggestive of EDO

Seminal vesiculography performed concurrently with SVA can determine the anatomic site of the obstruction

Genetic testing in patients with azoospermia

Chromosomal abnormalities Resulting in impaired testicular

function

Y-chromosome microdeletions leading to isolated spermatogenic

impairment.

In addition to mutations in the CFTR gene that give rise to CBAVD, genetic factors may play a role in nonobstructive forms of azoospermia.

The two most common

categories of genetic factors associated with nonobstructive

azoospermia are

Karyotypic chromosomal abnormalities

The frequency Of karyotypic abnormalities is inversely

proportional to the sperm count.

with a prevalence of 10-15 percent in azoospermic

men, approximately 5 percent in oligospermic men

and less than 1 percent in normospermic men.

Sex chromosomal aneuploidy (Klinefelter syndrome)

accounts for approximately two-thirds of chromosomal

abnormalities observed in infertile men.

Structural abnormalities of the autosomal

chromosomes, such as inversions and translocations,

are also observed at a higher frequency in infertile men

than in the general population.

When the male has gross karyotypic abnormalities, the

couple is at increased risk for miscarriages and for

having children with chromosomal and congenital

defects and infertility in male offspring

Karyotyping should be offered to men who have nonobstructive azoospermia or severe oligospermia

prior to performing ICSI with their sperm.

Y-chromosome microdeletions

Microdeletions of the Y chromosome may be found in 10-15 percent of men with azoospermia or severe oligospermia .

The human Y chromosome plays an essential role in

the genetic regulation of spermatogenesis.

Most of the genes involved in spermatogenesis have been mapped to the proximal long arm of the Y chromosome (Yq11) and are arranged in azoospermia factor (AZF) region. deletions in this region are specifically related to failure of spermatogenesis.

Azoospermia factor region (AZF region) contains genes involved in the growth and development of sperm and contains three subregions:

AZFa (proximal)

AZFb (central)

AZFc (distal)

These microdeletions are too small to be

detected by karyotyping but can be

found by using polymerase chain reaction

(PCR)

It appears That these regions of the Y chromosome contain multiple genes necessary for spermatogenesis.

The specific location of the deletion along the Y chromosome may significantly affect spermatogenesis. If the deleted region of the Y chromosome is in the AZFc region, sperm will be present in the ejaculate in many patients, albeit in severely reduced numbers.

Other patients with AZFc region deletions will be azoospermic but still may have sperm production that is sufficient to allow sperm extraction by testis biopsy.

However, up to 80% of men with AZFc deletions may have retrievable sperm for ICSI.

The presence of a deletion involving the entire AZFb region,

however, appears to predict a very poor prognosis for sperm

Retrieval despite extensive testicular biopsies .

Poor Sperm retrieval results may also exist for men with

deletions involving the AZFa region.

Sons of individuals with a Y-chromosome microdeletion will

inherit the microdeletion and may consequently be infertile.

Furthermore, the couple must be counseled on the

inheritance of this compromised fertility potential in all male

offspring

AZFa

The two main genes located in the AZFa region are USP9Y and DBY (also called DDX3Y).

Deletions in the AZFa region that remove both of these genes

Sertoli cell–only syndrome (SCO)

Shortening or deletion of the USP9Y gene causes

Azoospermia

Oligozoospermia

Oligoasthenozoospermia

The DBY gene has a more critical role in spermatogenesis than the USP9Y gene

AZFb

Deletions of the AZFb region cause arrest of spermatogenesis at the primary spermatocyte stage, indicating that the region is essential for fertility

The main genes in the AZFb region is RBMY and a family of PRY genes.

RBMY1 codes for an RNA binding protein , which is a testis-specific splicing factor expressed in the nuclei of spermatogonia, spermatocytes, and round spermatids.

The PRY genes are involved in the regulation of apoptosis,

(an essential process that removes abnormal sperm)

If both the RBMY and PRY genes are removed, spermatogenesis is arrested completely

AZFc

Studies demonstrate that only the AZFa and AZFb regions are needed to initiate spermatogenesis but without the AZFc region, spermatogenesis will not be completely normal

The AZFc region also contains genes involved in spermatogenesis.The DAZ (deleted in Azoospermia) gene which encodes a transcription factor that is usually present in men with Normal fertility, is located in the AZFc region.AZFc deletions cause approximately 12% of non-obstructive azoospermia and 6% of severe oligozoospermia.In many cases, men can still achieve fertilization with the assistance of ART.

Thanks for your attention….