Azoospermia

Azoospermia
Azoospermia
Classification and external resources

Semen analysis revealing no sperm cells and multiple white blood cells
ICD-10 N46
ICD-9 606.0

Azoospermia is the medical condition of a male not having any measurable level of sperm in his semen. It is associated with very low levels of fertility or even sterility, but many forms are amenable to medical treatment. In humans, azoospermia affects about 1% of the male population[1] and may be seen in up to 20% of male infertility situations.[2]

Contents

Classification

Azoospermia can be classified into three major types as listed.[2] Many conditions listed may also cause various degrees of oligospermia rather than azoospermia.

Pretesticular azoospermia

Pretesticular azospermia is characterized by inadequate stimulation of otherwise normal testicles and genital tract. Typically, follicle-stimulating hormone (FSH) levels are low (hypogonadotropic) commensurate with inadequate stimulation of the testes to produce sperm. Examples include hypopituitarism (for various causes), hyperprolactinemia, and exogenous FSH suppression by testosterone. Chemotherapy may suppress spermatogenesis.[3] Pretesticular azoospermia is seen in about 2% of azoospermia[2]

Testicular azoospermia

In this situation the testes are abnormal, atrophic, or absent, and sperm production severely disturbed to absent. FSH levels tend to be elevated (hypergonadotropic) as the feedback loop is interrupted. The condition is seen in 49-93% of men with azoospermia.[2] Testicular failure includes absence of failure production as well as low production and maturation arrest during the process of spermatogenesis.

Causes for testicular failure include congenital issues such as in certain genetic conditions (e.g. Klinefelter syndrome), some cases of cryptorchism or Sertoli cell-only syndrome as well as acquired conditions by infection (orchitis), surgery (trauma, cancer), radiation,[3] or other causes. Mast cells releasing inflammatory mediators appear to directly suppress sperm motility in a potentially reversible manner, and may be a common pathophysiological mechanism for many causes leading to inflammation.[4]

Generally, men with unexplained hypergonadotropic azoospermia need to undergo a chromosomal evaluation.

Posttesticular azoospermia

In posttesticular azoospermia sperm are produced but not ejaculated, a condition that affects 7-51% of azoospermic men.[2] The main cause is a physical obstruction (obstructive azoospermia) of the posttesticular genital tracts. The most common reason is a vasectomy done to induce contraceptive sterility.[5] Other obstructions can be congenital (example agenesis of the vas deferens as seen in certain cases of cystic fibrosis) or acquired, such as ejaculatory duct obstruction for instance by infection.

Ejaculatory disorders include retrograde ejaculation and anejaculation; in these conditions sperm are produced but not expelled.

Diagnosis and evaluation

Azoospermia is usually detected in the course of an infertility investigation. It is established on the basis of two semen analysis evaluations done at separate occasions (when the seminal specimen after centrifugation shows no sperm under the microscope) and requires a further work-up. The following work-up is recommended by the Canadian Urologic Association:[2]

The investigation includes a history, a physical examination including a thorough evaluation of the scrotum and testes, laboratory tests, and possibly imaging. History includes the general health, sexual health, past fertility, libido, and sexual activity. Past exposure to a number of agents needs to be queried including medical agents like hormone/steroid therapy, antibiotics (sulphasalazine), alpha-blockers, 5 alpha-reductase inhibitors, chemotherapeutic agents, pesticides, recreational drugs (marijuana, excessive alcohol), and heat exposure of the testes. A history of surgical procedures of the genital system needs to be elicited. The family history needs to assessed to look for genetic abnormalities.

Absence of the vas deferens may be detectable on physical examination and can be confirmed by a transrectal ultrasound (TRUS). If confirmed genetic testing for cystic fibrosis is in order. Retrograde ejaculation is diagnosed by examining a postejaculatory void for presence of sperm.

Low levels of LH and FSH with low or normal testosterone levels are indicative of pretesticular problems, while high levels of gonadotropins indicate testicular problems. However, often this distinction is not clear and the differentiation between obstructive versus non-obstructive azoospermia may require a testicular biopsy.

Serum inhibin-B weakly indicates presence of sperm cells in the testes, raising chances for successfully achieving pregnancy through testicular sperm extraction (TESE), although the association is not very substantial, having 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 the presence of sperm in the testes in non-obstructive azoospermia.[6]

It is recommended that men primary hypotituitarism may be linked to a genetic cause, a genetic evaluation is indicated in men with azoospermia due to primary hypopituitarism.[1] Azoospermic men with testicular failure are advised to undergo karyotype and Y-micro-deletion testing.[7][8]

Genetic causes of azoospermia

Genetic factors can cause pretesticular, testicular, and posttesticular azoospermia (or oligospermia) and include the following situations:[8] The frequency of chromosomal abnormalities is inverse proportional to the semen count, thus males with azoospermia are at risk to have a 10-15% abnormalities on karyotyping versus about <1 % in the fertile male population.[1]

Pretesticular azoospermia may be caused by congential hypopituitarism, Kallmann syndrome, Prader-Willi syndrome and other genetic conditions that lead to Gnrh or gonadotropin deficiency. Testicular azoospermia is seen in Klinefelter syndrome(XXY) and the XX male syndrome. In addition, 13 % of men with azoospermia have a defective spermatogenesis that is linked to defects of the Y chromosome.[8] Such defects tend to be de novo micro-deletions and affect usually the long arm of the chromosome. A section of the long arm of the Y chromosome has been termed Azoospermia Factor (AZF) at Yq11 and subdivided into AZFa, AZFb, AZFc and possibly more subsections. Defects in this area can lead to oligospermia or azoospermia, however, a tight genotype-phenotype correlation has not been achieved.[8] Spermatogenesis is defective with gene defects for the androgen receptor.

Posttesticular azoospermia can be seen with certain point mutations in the cystic fibrosis transmembrane conductance regulator (CFTR) gene commonly associated with congenital vas deferens abnormalities.

Genetic counselling is indicated for men with genetic causes of azoospermia. In terms of reproduction, it needs to be considered if the genetic defect could be transmitted to the offspring.

Treatment

Pre- and post-testicular azoospermia a frequently correctible, while testicular azoospermia is usually permanent.[1] In the former the cause of the azoospermia needs to be considered and it opens up possibilities to manage this situation directly. Thus men with azoospermia due to hyperprolactinemia may resume sperm production after treatment of hyperprolactinemia or men whose sperm production is suppressed by exogenous androgens are expected to produce sperm after cessation of androgen intake. In situations where the testes are normal but unstimulated gonadotropin therapy can be expected to induce sperm production.

A major advancement in recent years has been the introduction of IVF with ICSI which allows successful fertilization even with immature sperm or sperm obtained directly from testicular tissue. IVF-ICSI allows for pregnancy in couples where the man has irreversible testicular azoospermia as long as it is possible to recover sperm material from the testes. Thus men with non-mosaic Klinefelter's syndrome have fathered children using IVF-ICSI.[9] Pregnancies have been achieved in situations where azoospermia was associated with cryptorchism and sperm where obtained by testicular sperm extraction (TESE).[10]

In men with posttesticular azoospermia a number of approaches are available. For obstructive azoospermia IVF-ICSI or surgery can be used and individual factors need to be considered for the choice of treatment.[5] Medication may be helpful for retrograde ejaculation.

See also

-spermia,
Further information: Testicular infertility factors
view · talk · edit
(Oligo)spermia - few spermatozoa in semen
(Hypo)spermia - small semen volume
(A)spermia - complete lack of semen
(Azoo)spermia - absence of sperm cells in semen
(Terato)spermia - sperm with abnormal morphology
(Asthenozoo)spermia - reduced sperm motility

References

  1. ^ a b c d Male Infertility Best Practice Policy Committee of the American Urological Association; Practice Committee of the American Society for Reproductive Medicine (2001). Infertility: Report on Evaluation of the Azoospermic Male. American Urological Association; American Society for Reproductive Medicine. ISBN 978-0-9649702-8-1. http://urology.ucsf.edu/patientGuides/pdf/maleInf/Azoospermic%20Male.pdf. 
  2. ^ a b c d e f Jarvi, K; Lo, K; Fischer, A; Grantmyre, J; Zini, A; Chow, V; Mak, V (2010). "CUA Guideline: The workup of azoospermic males". Canadian Urological Association journal 4 (3): 163–7. PMC 2874589. PMID 20514278. http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=2874589. 
  3. ^ a b Dohle, Gert R (2010). "Male infertility in cancer patients: Review of the literature". International Journal of Urology 17 (4): 327–331. doi:10.1111/j.1442-2042.2010.02484.x. PMID 20202000. 
  4. ^ Menzies, F. M.; Shepherd, M. C.; Nibbs, R. J.; Nelson, S. M. (2010). "The role of mast cells and their mediators in reproduction, pregnancy and labour". Human Reproduction Update 17 (3): 383–396. doi:10.1093/humupd/dmq053. PMID 20959350. 
  5. ^ a b Practice Committee of ASRM, August 2008. "The management of infertility due to obstructive azzospermia". http://www.asrm.org/uploadedFiles/ASRM_Content/News_and_Publications/Practice_Guidelines/Educational_Bulletins/The_management_of_infertility(1).pdf. Retrieved June 14, 2010. 
  6. ^ Toulis, K. A.; Iliadou, P. K.; Venetis, C. A.; Tsametis, C.; Tarlatzis, B. C.; Papadimas, I.; Goulis, D. G. (2010). "Inhibin B and anti-Mullerian hormone as markers of persistent spermatogenesis in men with non-obstructive azoospermia: a meta-analysis of diagnostic accuracy studies". Human Reproduction Update 16 (6): 713–724. doi:10.1093/humupd/dmq024. PMID 20601364. 
  7. ^ Schlegel, PN (2004). "Causes of azoospermia and their management". Reproduction, fertility, and development 16 (5): 561–72. doi:10.1071/RD03087. PMID 15367371. http://www.publish.csiro.au/journals/abstractHTML.cfm?J=RD&V=16&I=5&F=RD03087abs.XML. 
  8. ^ a b c d Poongothai, J; Gopenath, TS; Manonayaki, S (2009). "Genetics of human male infertility". Singapore medical journal 50 (4): 336–47. PMID 19421675. 
  9. ^ Fullerton, G.; Hamilton, M.; Maheshwari, A. (2010). "Should non-mosaic Klinefelter syndrome men be labelled as infertile in 2009?". Human Reproduction 25 (3): 588–597. doi:10.1093/humrep/dep431. PMID 20085911. 
  10. ^ Haimov-Kochman, R.; Prus, D.; Farchat, M.; Bdolah, Y.; Hurwitz, A. (2010). "Reproductive outcome of men with azoospermia due to cryptorchidism using assisted techniques". International Journal of Andrology 33 (1): e139–e143. doi:10.1111/j.1365-2605.2009.00977.x. PMID 19622071. 

Wikimedia Foundation. 2010.

Игры ⚽ Нужен реферат?

Look at other dictionaries:

  • Azoospermia — Saltar a navegación, búsqueda Azoospermia Clasificación y recursos externos Aviso médico CIE 10 N46, n40 …   Wikipedia Español

  • azoospermia — f. sex. Falta de espermatozoides en el esperma a causa de una incapacidad para ser sintetizados en el testículo o por una obstrucción en las vías de expulsión. Medical Dictionary. 2011. azoospermia …   Diccionario médico

  • azoospermia — azoospermia. См. азооспермия. (Источник: «Англо русский толковый словарь генетических терминов». Арефьев В.А., Лисовенко Л.А., Москва: Изд во ВНИРО, 1995 г.) …   Молекулярная биология и генетика. Толковый словарь.

  • azoospermia — azoospermia. f. Med. Carencia considerable de espermatozoides en el semen …   Enciclopedia Universal

  • azoospermia — s. f. [Medicina] Ausência de espermatozoides no esperma.   ‣ Etimologia: grego ázoos, on, sem vida + spermo + ia …   Dicionário da Língua Portuguesa

  • azoospermia — f. Med. Carencia considerable de espermatozoides en el semen …   Diccionario de la lengua española

  • Azoospermia — No sperm at all. The ejaculate is completely devoid of sperm. By contrast, in oligospermia (literally, few sperm) there are some sperm, but fewer than normal. * * * Absence of living spermatozoa in the semen; failure of spermatogenesis. SEE ALSO …   Medical dictionary

  • azoospermia — aspermia; n. the complete absence of sperm from the seminal fluid. This is due either to profound impairment of sperm formation (spermatogenesis) due to damage to the testes (e.g. caused by cryptorchidism, mumps orchitis, or radio or… …   The new mediacal dictionary

  • azoospermia — noun Etymology: New Latin, from Greek azoos lifeless (from a 2a + zōē life) + sperma semen, seed more at sperm Date: circa 1881 absence of spermatozoa from the seminal fluid …   New Collegiate Dictionary

  • azoospermia — noun The absence of live sperm in the semen …   Wiktionary

Share the article and excerpts

Direct link
Do a right-click on the link above
and select “Copy Link”