Azoospermia is a medical condition of a man whose semen does not contain sperm. It is associated with infertility, but many forms are receiving medical treatment. In humans, azoospermia affects about 1% of the male population and can be seen in up to 20% of male infertility situations.
Video Azoospermia
Classification
Azoospermia can be classified into three main types as listed. Many conditions listed can also cause varying degrees of oligospermia rather than azoospermia.
Pretesticular
Pretesticular azoospermia is characterized by inadequate stimulation of the normal testes and genital tract. Usually, a low follicle-stimulating hormone (FSH) level (hypogonadotropic) is equivalent to inadequate testicular stimulation to produce sperm. Examples include hypopituitarism (for various causes), hyperprolactinaemia, and exogenous FSH suppression by testosterone. Chemotherapy can suppress spermatogenesis. Pretesticular Azoospermia is seen in about 2% of azoospermia. Azoospermia Pretesticular is a non-obstructive azoospermia.
Testicular
In this situation the testes are abnormal, atrophy, or absent, and sperm production is severely disrupted until it is absent. FSH levels tend to increase (hypergonadotropic) as the feedback loop is disturbed (lack of inhibition of feedback on FSH). This condition is seen in 49-93% of men with azoospermia. Testicular failure includes the absence of production failure and poor production and maturation capture during the spermatogenesis process.
Causes for testicular failure include congenital problems such as certain genetic conditions (eg Klinefelter's syndrome), some cases of cryptorchidism or Sertoli cell-only syndrome and conditions acquired by infection (orchitis), surgery (trauma, cancer, radiation, or other causes). Mast cells that release inflammatory mediators appear to directly repress sperm motility in a reversible way, and may be a common pathophysiologic mechanism for many causes that cause inflammation. Testicular Azoospermia is a non-obstructive type of azoospermia.
Generally, men with unexplained hypergonadotropic azoospermia need to undergo chromosome evaluation.
Posttesticular
Postproduction azoospermia pascornus is produced but does not ejaculate, a condition that affects 7-51% of azoospermic men. The main cause is the physical obstruction (obstructive azoospermia) of the posttesticular genital tract. The most common reason is that vasectomy is done to induce contraceptive sterility. Other obstruction may be congenital (eg, agenesis vas deferens as seen in certain cases of cystic fibrosis) or acquired, such as ducted ejaculation obstruction eg by infection.
Impaired ejaculation including retrograde ejaculation and anejaculation; in this condition the sperm is produced but not discarded.
Unknown
Idiopathic idiopathic is where no known cause of this condition. This may be caused by several risk factors, such as age and weight. For example, a review in 2013 came to the result that oligospermia and azoospermia were significantly associated with overweight (odds ratio 1.1), obesity (odds ratio 1.3) and morbid obesity (odds ratio 2.0), but the cause is unknown. The review found no significant association between oligospermia and lean.
Maps Azoospermia
Genetics
Genetic factors can cause pretesticular, testicular, and posttesticular azoospermia (or oligospermia) and include the following situation: The frequency of chromosomal abnormalities is inversely proportional to the amount of semen, so men with azoospermia risk having 10-15% (other sources cite 15-20% incidence) abnormalities in karyotyping versus about & lt; 1% in a fertile male population.
Pretesticular azoospermia may be caused by congenital hypopituitarism, Kallmann's syndrome, Prader-Willi syndrome and other genetic conditions that cause GnRH or gonadotropin deficiency. Testicular Azoospermia seen in Klinefelter syndrome (XXY) and male XX syndrome. In addition, 13% of men with azoospermia have a damaged spermatogenesis associated with Y chromosome defects. Such defects tend to de novo micro-deletions and usually affect the long arm of the chromosome. The long-arm portion of the Y chromosome has been called the Azoospermia Factor (AZF) in Yq11 and subdivided into AZFa, AZFb, AZFc and possibly more subsections. Defects in this area may cause oligospermia or azoospermia, however, strict correlation of genotypes has not been achieved. Spermatogenesis is damaged by gene defects for androgen receptors.
Posttikular Azoospermia may be seen with a particular point mutation in the transmembrane corsis gene conductance regulator (CFTR) cystic fibrosis commonly associated with congenital vas deferens abnormalities.
Genetic counseling is indicated for men with genetic causes of azoospermia. In the case of reproduction, consideration should be given if genetic defect can be transmitted to the offspring.
BRD7
BRD7, a transcriptional regulatory protein, is usually highly expressed in the testes. The presence or decrease in BRD7 protein expression was observed in the testes of azoospermic patients demonstrating spermatogenesis capture. Homozygous KO rat [ BRD7 (-/-)] is infertile and has higher levels of apoptosis and DNA damage in their germline cells.
Gene polymorphism
The human breast cancer vulnerability gene 2 ( BRCA2 ) is used in DNA repair. Single common nucleotide polymorphisms at BRCA2 are associated with idiopathic male infertility with azoospermia.
The four genes involved in repairing double-stranded DNA and chromosome synapses ( TEX11 , TEX15 , MLH1 and MLH3 ) key roles in genomic integrity, meiotic recombination and gametogenesis. Polymorphisms in this gene were tested for association with male infertility. Single nucleotide polymorphisms in these two genes ( TEX11 and MLH3 ) were found to be associated with male infertility involving azoospermi or oligospermia.
Diagnosis
Azoospermia is usually detected in the course of infertility investigations. It was founded on the basis of two semen analysis evaluations performed on separate occasions (when seminal specimens after centrifugation did not show sperm under a microscope) and required further examination.
Examinations include history, physical examination including a thorough evaluation of the scrotum and testes, laboratory tests, and possible imaging. History includes general health, sexual health, past fertility, libido, and sexual activity. Previous exposure to a number of agents should be asked including medical agents such as hormone/steroid therapy, antibiotics, 5-ASA inhibitors, alpha-blockers, 5 alpha-reductase inhibitors, chemotherapeutic agents, pesticides, recreational drugs (marijuana, ), and exposure to heat on the testes. The history of the surgical procedure of the genital system needs to be raised. Family history needs to be assessed to look for genetic disorders.
Congenital vas deferens loss can be detected on physical examination and can be confirmed by transrectal ultrasound (TRUS). If genetic testing is confirmed for cystic fibrosis in order. Transrectal ultrasound can also assess azoospermia caused by obstruction, or anomalies associated with ejaculatory duct obstruction, such as abnormalities within the duct itself, median prostate cyst (indicating cyst aspiration requirement), or damage to seminal vesicles. to be enlarged or emptied. Retrograde ejaculation is diagnosed by examining post-operative urine for the presence of sperm after making alkali and centrifugation.
Low LH and FSH levels with low or normal testosterone levels are indicative of pretesticular problems, while high levels of gonadotropin indicate testicular problems. However, often these differences are unclear and the differentiation between obstructive versus non-obstructive azoospermia may require testicular biopsy. On the other hand, "In men with azoospermia with normal ejaculatory volume, the serum FSH level greater than twice the upper limit of the normal range is a reliable diagnostic of dysfunctional spermatogenesis and, when found, diagnostic testicular biopsy is usually unnecessary, although no consensus exists in this case. "But also, the very high FSH rate (& gt; 45 ID/mL) has been correlated with the successful extraction of testicular sperm microsissection.
A weak inhibin-B serum indicates the presence of sperm cells in the testes, increasing the chances of successfully achieving pregnancy through testicular sperm extraction (TESE), although the association is not very large, has a sensitivity of 0.65 (95% confidence interval [CI]: 0.56- 0.74) and a specificity of 0.83 (CI: 0.64-0.93) for prediction of sperm presence in the testes in non-obstructive azoospermia.
Seminal plasma proteins TEX101 and ECM1 have recently been proposed for the differential diagnosis of azoospermic forms and subtypes, and for the prediction of TESE results. Mount Sinai Hospital, Canada begins clinical trials to test this hypothesis by 2016.
It is suggested that primary male hypopituitarism may be related to genetic causes, genetic evaluation is shown in men with azoospermia due to primary hypopituitarism. Azoospermic men with testicular failure are advised to undergo karyotype and Y-micro-removal tests.
Treatment
Pre-and post-testicular Azoospermia can often be corrected, whereas testicular azoospermia is usually permanent. In the former, the cause of azoospermia needs to be considered and opens the possibility of managing this situation directly. So men with azoospermia because hyperprolactinaemia can continue sperm production after hyperprolactinemia treatment or men whose sperm production is suppressed by exogenous andogen is expected to produce sperm after discontinuation of androgen intake. In situations where the testes are normal but not stimulated, gonadotropin therapy can be expected to induce sperm production.
The great advancement in recent years is the introduction of IVF with ICSI that allows successful conception even with immature sperm or sperm obtained directly from testicular tissue. IVF-ICSI allows for couples pregnancies in which men have irreversible testicular azoospermia as long as possible to recover sperm material from the testes. Thus the man with Klinefelter's non-mosaic syndrome has become the father of children using IVF-ICSI. Pregnancy has been achieved in situations where azoospermia is associated with cryptorchism and sperm where it is obtained by testicular sperm extraction (TESE).
In men with postnatal azoospermia, a number of approaches are available. For obstructive Azoospermia, IVF-ICSI or surgery may be used and individual factors need to be considered for treatment options. Medication may be helpful for retrograde ejaculation.
See also
- Infertility
- Retrograde ejaculation
- Vasectomy
References
Source of the article : Wikipedia
0 Comments