Wikipedia

Male infertility

(Redirected from Vas deferens obstruction)

Male infertility refers to a sexually mature male's inability to impregnate a fertile female.[1] In humans, it accounts for 40–50% of infertility.[2][3][4][5] It affects approximately 7% of all men.[6] Male infertility is commonly due to deficiencies in the semen, and semen quality is used as a surrogate measure of male fecundity.[7] More recently, advance sperm analyses that examine intracellular sperm components are being developed.[2][8]

Male infertility
SpecialtyUrology

Age considerations

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Sperm motility increases from puberty through one's mid-thirties. Research shows that from the age of 36 onwards, sperm motility decreases from 40% Grade A & B to 31% in one's 50s. The effects of aging on semen quality is summarized below based on a study of 1,219 subjects:[9]

Age group (years) Number of subjects (n) Motility (% Grade A+B)

[Min-Max]

21-28 57 47.5 ± 25.4

[0-88]

29-35 450 48.1 ± 30.4

[0-95]

36-42 532 40.0 ± 27.1

[0-83]

43-49 165 33.1 ± 25.1

[0-84]

50-60 15 31.3 ± 23.9

[0-59]

90% of seminiferous tubules in men in their 20s and 30s contain spermatids, whereas men in their 40s and 50s have spermatids in 50% of their seminiferous tubules, and only 10% of seminiferous tubules from men aged > 80 years contain spermatids.[10][11] In a random international sample of 11,548 men confirmed to be biological fathers by DNA paternity testing, the oldest father was found to be 66 years old at the birth of his child; the ratio of DNA-confirmed versus DNA-rejected paternity tests around that age is in agreement with the notion of general male infertility above age 65–66.[12][13]

Causes

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Factors relating to male infertility include:[14]

Immune infertility

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Antisperm antibodies (ASA) have been considered as infertility cause in around 10–30% of infertile couples.[15] ASA production are directed against surface antigens on sperm, which can interfere with sperm motility and transport through the female reproductive tract, inhibiting capacitation and acrosome reaction, impaired fertilization, influence on the implantation process, and impaired growth and development of the embryo. Risk factors for the formation of antisperm antibodies in men include the breakdown of the blood‑testis barrier, trauma and surgery, orchitis, varicocele, infections, prostatitis, testicular cancer, failure of immunosuppression and unprotected receptive anal or oral sex with men.[15][16]

Genetics

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See also: Genetics of infertility

Chromosomal anomalies and genetic mutations account for nearly 10–15% of all male infertility cases.[17]

Mitochondrial DNA

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Mature human sperm contains almost no mitochondrial DNA at all. An increased amount of mitochondrial DNA in the sperm cells has shown to have a negative impact on fertility.[18][19]

Klinefelter syndrome

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One of the most commonly known causes of infertility is Klinefelter syndrome, which affects one in 500–1000 newborn males.[20] Klinefelter syndrome is a chromosomal defect that occurs during gamete formation due to a non-disjunction error during cell division. Resulting in males having smaller testes, reducing the amount of testosterone and sperm production.[21] Males with this syndrome carry an extra X chromosome (XXY), meaning they have 47 chromosomes compared to the normal 46 in each cell. This extra chromosome directly affects sexual development before birth and during puberty. A variation of Klinefelter syndrome is when some cells in an individual have the extra X chromosome but others do not, referred to as mosaic Klinefelter syndrome. The reduction of testosterone in the male body normally results in an overall decrease in the production of viable sperm for these individuals thereby forcing them to turn to fertility treatments to father children.[20]

Y chromosome deletions

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Y chromosomal infertility is a direct cause of male infertility due to its effects on sperm production, occurring in approximately one in 2000 males.[22] Usually, affected men show no symptoms, although they may have smaller testes. Men with this condition may exhibit azoospermia (no sperm production), oligozoospermia (small number of sperm production), or they may produce abnormally shaped sperm (teratozoospermia).[22] This case of infertility occurs during the development of gametes in the male. Where a normal healthy male will have both an X and a Y chromosome, affected males have genetic deletions in the Y chromosome. These deletions affect protein production that is vital for spermatogenesis. Studies have shown that this is an inherited trait; if a male is fathered by a man who also exhibited Y chromosome deletions then this trait will be passed down.[citation needed] These individuals are thereby "Y-linked". Daughters are not affected and cannot be carriers due to their lack of a Y chromosome.

Other

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Pre-testicular causes

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Pre-testicular factors refer to conditions that impede adequate support of the testes and include situations of poor hormonal support and poor general health including:

Varicocele

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Varicocele is a condition of swollen testicle veins.[27]

It is present in 15% of normal men and in about 40% of infertile men.

It is present in up to 35% of cases of primary infertility and 69–81% of secondary infertility.[28]

Tobacco smoking

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See also: Smoking and pregnancy

There is increasing evidence that the harmful products of tobacco smoking may damage the testicles[34] and kill sperm,[35][36] but their effect on male fertility is not clear.[37] Some governments require manufacturers to put warnings on packets. Smoking tobacco increases intake of cadmium, because the tobacco plant absorbs the metal. Cadmium, being chemically similar to zinc, may replace zinc in the DNA polymerase, which plays a critical role in sperm production. Zinc replaced by cadmium in DNA polymerase can be particularly damaging to the testes.[38]

DNA damage

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Common inherited variants in genes that encode enzymes employed in DNA mismatch repair are associated with increased risk of sperm DNA damage and male infertility.[39] As men age there is a consistent decline in semen quality, and this decline appears to be due to DNA damage.[40] The damage manifests by DNA fragmentation and by the increased susceptibility to denaturation upon exposure to heat or acid, the features characteristic of apoptosis of somatic cells.[41] These findings suggest that DNA damage is an important factor in male infertility.[citation needed]

Epigenetic

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See also: DNA methylation

An increasing amount of recent evidence has been recorded documenting abnormal sperm DNA methylation in association with abnormal semen parameters and male infertility.[42][43] Until recently, scientists have thought that epigenetic markers only affect the individual and are not passed down due to not changing the DNA.[44] New studies suggest that environmental factors that changed an individual's epigenetic markers can be seen in their grandchildren, one such study demonstrating this through rats and fertility disruptors.[44] Another study bred rats exposed to an endocrine disruptor, observing effects up to generation F5 including decreased sperm motility and decreased sperm count.[45] These studies suggest that environmental factors that influence fertility can be felt for generations even without changing the DNA.[citation needed]

Post-testicular causes

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Post-testicular factors decrease male fertility due to conditions that affect the male genital system after testicular sperm production and include defects of the genital tract as well as problems in ejaculation:[citation needed]

Diagnostic evaluations

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The diagnosis of infertility begins with a medical history and physical exam by a physician, physician assistant, or nurse practitioner. Typically two separate semen analyses will be required. The provider may order blood tests to look for hormone imbalances, medical conditions, or genetic issues.[citation needed]

Medical history

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The history should include prior testicular or penile insults (torsion, cryptorchidism, trauma), infections (mumps orchitis, epididymitis), environmental factors, excessive heat, radiation, medications, and drug use (anabolic steroids, selective serotonin reuptake inhibitors, alcohol, smoking). Sexual habits, frequency and timing of intercourse, use of lubricants, and each partner's previous fertility experiences are important. Loss of libido and headaches or visual disturbances may indicate a pituitary tumor.[citation needed]

The past medical or surgical history may reveal thyroid or liver disease (abnormalities of spermatogenesis), diabetic neuropathy (retrograde ejaculation), radical pelvic or retroperitoneal surgery (absent seminal emission secondary to sympathetic nerve injury), or hernia repair (damage to the vas deferens or testicular blood supply).[citation needed]

A family history may reveal genetic problems.

Physical examination

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Usually, the patient disrobes completely and puts on a gown. The physician, physician assistant, or nurse practitioner will perform a thorough examination of the penis, scrotum, testicles, I vas deferens, spermatic cords, ejaculatory ducts, urethra, urinary bladder, anus and rectum. An orchidometer can measure testicular volume, which in turn is tightly associated with both sperm and hormonal parameters.[6] A physical exam of the scrotum can reveal a varicocele, but the impact of detecting and surgically correct a varicocele on sperm parameters or overall male fertility is debated.[6]

Sperm sample

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Semen sample obtaining

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Semen sample obtaining is the first step in spermiogram. The optimal sexual abstinence for semen sample obtaining is of 2–7 days. The first way to obtain the semen sample is through masturbation, and the best place to obtain it is in the same clinic, as this way temperature changes during transport can be avoided, which can be lethal for some spermatozoa.

A single semen sample is not determining for disease diagnosis, so two different samples have to be analyzed with an interval between them of seven days to three months, as sperm production is a cyclic process. It is prudent to ask about possible sample loss, as that could mask true results of spermiogram.

To obtain the sample, a sterile plastic recipient is put directly inside, always no more than one hour before being studied. Conventional preservatives should not be used, as they have chemical substances as lubricants or spermicides that could damage the sample. If preservatives have to be used, for cases of religious ethics in which masturbation is forbidden, a preservative with holes is used. In case of paraplegia it is possible to use mechanic tools or electroejaculation.

The sample should never be obtained through coitus interruptus for several reasons:

  • Some part of ejaculation could be lost.
  • Bacterial contamination could happen.
  • The acid vaginal pH could be deleterious for sperm motility.

Also is very important to label the sample correctly the recipient with patient identification, date, hour, abstinence days, among other data required to be known.

Main article: Semen analysis
Further information: Semen quality

The volume of the semen sample (must be more than 1.5 ml), approximate number of total sperm cells, sperm motility/forward progression, and % of sperm with normal morphology are measured. It is possible to have hyperspermia (high volume more than 6 ml) or Hypospermia (low volume less than 0.5 ml). This is the most common type of fertility testing.[46][47] Semen deficiencies are often labeled as follows:

  • Oligospermia or oligozoospermia – decreased number of spermatozoa in semen
  • Aspermia – complete lack of semen
  • Hypospermia – reduced seminal volume
  • Azoospermia – absence of sperm cells in semen
  • Teratospermia – increase in sperm with abnormal morphology
  • Asthenozoospermia – reduced sperm motility
  • Necrozoospermia – all sperm in the ejaculate are dead
  • Leucospermia – a high level of white blood cells in semen
  • Normozoospermia or normospermia – It is a result of semen analysis that shows normal values of all ejaculate parameters by WHO but still there are chances of being infertile. This is also called as unexplained Infertility[citation needed]

There are various combinations of these as well, e.g. Teratoasthenozoospermia, which is reduced sperm morphology and motility. Low sperm counts are often associated with decreased sperm motility and increased abnormal morphology, thus the terms "oligoasthenoteratozoospermia" or "oligospermia" can be used as a catch-all.

Special obtaining

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– Psychotherapy

– Intercourses with special preservatives without lubricants or spermicides. In case of religion limitations we should use a SCD, or Seminal Collection Device, such as preservatives with holes.

– Drug stimulation

– Percutaneous spermatozoa obtaining directly from epididymis, testes, etc.

– Vibro-stimulation

– Electro-stimulation

This type of ejaculation happens when there is a defect on prostate, so the sample is not ejaculated outside but to the bladder. So, in that case, what we have to do to obtain the sample is:

– Intake bicarbonate, about 25 grams, the night before and the morning of the sample obtaining. This will neutralize acidic urine and will turn it alkaline, near semen's pH, so spermatozoa can survive.

– Before masturbation we have to urinate to empty the bladder. This must go to the first recipient.

– Just after that, the subject has to masturbate and ejaculate, obtaining then a new urine sample with ejaculation that will be stored on the second recipient.

– Finally we have to obtain the next urine, 2nd urine, for potential ejaculation fraction, which will be stored in the third recipient. This may contain the most important fraction.

Blood sample

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Common hormonal test include determination of FSH and testosterone levels. A blood sample can reveal genetic causes of infertility, e.g. Klinefelter syndrome, a Y chromosome microdeletion, or cystic fibrosis.[citation needed]

Ultrasonography

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Scrotal ultrasonography is useful when there is a suspicion of some particular diseases. It may detect signs of testicular dysgenesis, which is often related to an impaired spermatogenesis and to a higher risk of testicular cancer.[6] Scrotum ultrasonography may also detect testicular lesions suggestive of malignancy. A decreased testicular vascularization is characteristic of testicular torsion, whereas hyperemia is often observed in epididymo-orchitis or in some malignant conditions such as lymphoma and leukemia.[6] Doppler ultrasonography useful in assessing venous reflux in case of a varicocele, when palpation is unreliable or in detecting recurrence or persistence after surgery, although the impact of its detection and surgical correction on sperm parameters and overall fertility is debated.[6]

Dilation of the head or tail of the epididymis is suggestive of obstruction or inflammation of the male reproductive tract.[6] Such abnormalities are associated with abnormalities in sperm parameters, as are abnormalities in the texture of the epididymis.[6] Scrotal and transrectal ultrasonography (TRUS) are useful in detecting uni- or bilateral congenital absence of the vas deferens (CBAVD), which may be associated with abnormalities or agenesis of the epididymis, seminal vesicles or kidneys, and indicate the need for testicular sperm extraction.[6] TRUS plays a key role in assessing azoospermia caused by obstruction, and detecting distal CBAVD or anomalies related to obstruction of the ejaculatory duct, such as abnormalities within the duct itself, a median cyst of the prostate (indicating a need for cyst aspiration), or an impairment of the seminal vesicles to become enlarged or emptied.[6]

Hyposmotic test

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To check if the plasma membrane of the sperm is working properly or if it is damaged. To do this, the spermatozoa are placed in a hypotonic medium (low in salts), which causes an osmotic imbalance in the cells, causing the medium to enter the interior of the spermatozoon and swell it. If the sperm membrane is damaged, it will not be functional, so fertilization cannot take place. Hence the relevance of this test.[48]

Sperm FISH

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To check if the spermatozoa have a normal set of chromosomes. It provides great information about the seminal quality of the male. It is performed by marking specific chromosomes of the sperm with fluorescent DNA probes. Some situations in which sperm FISH is indicated are the following:

-Alterations in the karyotype. -Altered seminogram, especially in cases with low concentration or serious morphology problems. -Man undergoing chemotherapy or radiotherapy. -Couples with recurrent miscarriages of unknown cause. -Implantation failure on repeated occasions after applying assisted reproductive techniques. -Couples who have had a child with some chromosomal alteration. Advanced age.[49]

Prevention

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Some strategies suggested or proposed for avoiding male infertility include the following:

  • Avoiding smoking[50] as it damages sperm DNA
  • Avoiding heavy marijuana and alcohol use.[51]
  • Avoiding excessive heat to the testes.[51]
  • Maintaining optimal frequency of coital activity: sperm counts can be depressed by daily coital activity[51] and sperm motility may be depressed by coital activity that takes place too infrequently (abstinence 10–14 days or more).[51]
  • Wearing a protective cup and jockstrap to protect the testicles, in any sport such as baseball, football, cricket, lacrosse, hockey, softball, paintball, rodeo, motocross, wrestling, soccer, karate or other martial arts or any sport where a ball, foot, arm, knee or bat can come into contact with the groin.
  • Diet: Healthy diets (i.e. the Mediterranean diet[52]) rich in such nutrients as omega-3 fatty acids, some antioxidants and vitamins, and low in saturated fatty acids (SFAs) and trans-fatty acids (TFAs) are inversely associated with low semen quality parameters. In terms of food groups, fish, shellfish and seafood, poultry, cereals, vegetables and fruits, and low-fat dairy products have been positively related to sperm quality. However, diets rich in processed meat, soy foods, potatoes, full-fat dairy products, coffee, alcohol and sugar-sweetened beverages and sweets have been inversely associated with the quality of semen in some studies. The few studies relating male nutrient or food intake and fecundability also suggest that diets rich in red meat, processed meat, tea and caffeine are associated with a lower rate of fecundability. This association is only controversial in the case of alcohol. The potential biological mechanisms linking diet with sperm function and fertility are largely unknown and require further study.[53]

Treatment

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Treatments vary according to the underlying disease and the degree of the impairment of the male's fertility. Further, in an infertility situation, the fertility of the female needs to be considered.[54]

Pre-testicular conditions can often be addressed by medical means or interventions.

Testicular-based male infertility tends to be resistant to medication. Usual approaches include using the sperm for intrauterine insemination (IUI), in vitro fertilization (IVF), or IVF with intracytoplasmatic sperm injection (ICSI). With IVF-ICSI even with a few sperm pregnancies can be achieved.

Obstructive causes of post-testicular infertility can be overcome with either surgery or IVF-ICSI. Ejaculatory factors may be treatable by medication, or by IUI therapy or IVF.

Vitamin E helps counter oxidative stress,[55] which is associated with sperm DNA damage and reduced sperm motility.[56][57] A hormone-antioxidant combination may improve sperm count and motility.[58][57] Giving oral antioxidants to men in couples undergoing in vitro fertilisation for male factor or unexplained subfertility may lead to an increase in the live birth rate but overall the risk of adverse effects is unclear.[59]

Hormonal therapy

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See also: Spermatogenesis § Hormonal control

Administration of luteinizing hormone (LH) (or human chorionic gonadotropin) and follicle-stimulating hormone (FSH) is very effective in the treatment of male infertility due to hypogonadotropic hypogonadism.[60] Although controversial,[61] off-label clomiphene citrate, an antiestrogen, may also be effective by elevating gonadotropin levels.[60]

Though androgens are absolutely essential for spermatogenesis and therefore male fertility, exogenous testosterone therapy has been found to be ineffective in benefiting men with low sperm count.[62] This is thought to be because very high local levels of testosterone in the testes (concentrations in the seminiferous tubules are 20- to 100-fold greater than circulating levels)[63] are required to mediate spermatogenesis, and exogenous testosterone therapy (which is administered systemically) cannot achieve these required high local concentrations (at least not without extremely supraphysiological dosages).[62] Moreover, exogenous androgen therapy can actually impair or abolish male fertility by suppressing gonadotropin secretion from the pituitary gland, as seen in users of androgens/anabolic steroids (who often have partially or completely suppressed sperm production).[60][62] This is because suppression of gonadotropin levels results in decreased testicular androgen production (causing diminished local concentrations in the testes)[60][62] and because FSH is independently critical for spermatogenesis.[64][65] In contrast to FSH, LH has little role in male fertility outside of inducing gonadal testosterone production.[66]

Estrogen, at some concentration, has been found to be essential for male fertility/spermatogenesis.[67][68] However, estrogen levels that are too high can impair male fertility by suppressing gonadotropin secretion and thereby diminishing intratesticular androgen levels.[62] As such, clomiphene citrate (an antiestrogen) and aromatase inhibitors such as testolactone or anastrozole have shown effectiveness in benefiting spermatogenesis.[62]

Low-dose estrogen and testosterone combination therapy may improve sperm count and motility in some men,[69] including in men with severe oligospermia.[70]

Research

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Researchers at Münster University developed in vitro culture conditions using a three-dimensional agar culture system which induces mouse testicular germ cells to reach the final stages of spermatogenesis, including spermatozoa generation.[71] If reproduced in humans, this could potentially enable infertile men to father children with their own sperm.[72][73]

Researchers from Montana State University developed precursors of sperm from skin cells of infertile men.[74][75][76]

Sharpe et al. comment on the success of intracytoplasmic sperm injection (ICSI) in women saying, "[t]hus, the woman carries the treatment burden for male infertility, a fairly unique scenario in medical practice. Ironically, ICSI's success has effectively diverted attention from identifying what causes male infertility and focused research onto the female, to optimize the provision of eggs and a receptive endometrium, on which ICSI's success depends."[77][78]

Prevalence

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Currently, there are no solid numbers on how many couples worldwide experience infertility, but the World Health Organization estimates between 60 and 80 million couples are affected. The population in different regions have varying amounts of infertility.

Starting in the late 20th century, scientists have expressed concerns about the declining semen quality in men. A study was done in 1992 with men who had never experienced infertility showed that the amount of sperm in semen had declined by 1% per year since 1938.[79][80] Further research a few years later also confirmed the decline in sperm count and also seminal volume.[81] Various studies in Finland, Southern Tunisia, and Argentina also showed a decline in sperm count, motility, morphology, and seminal volume.

Males from India had a 30.3% decline in sperm count, 22.9% decline in sperm motility, and a 51% decrease in morphology over a span of a decade. Doctors in India disclosed that the sperm count of a fertile Indian male had decreased by a third over a span of three decades.[82] Some factors may include exposure to high temperatures at places such as factories. A 1 degree increase in temperature will reduce 14% of spermatogenesis.[83]

Researchers in Calcutta conducted a study between 1981 and 1985 that also showed a decrease in sperm motility and seminal volume, but no change in sperm concentration.[84]

Society and culture

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Main article: Infertility and childlessness stigmas

There are a variety of social stigmas that surround male infertility throughout the world. The condition and its effects on both men and women is the topic for example of the novel set in Nigeria entitled, The Secret Lives of Baba Segin's Wives. A lot of research has pointed to the relationship between infertility and emasculation.[85][86][87] This association has led to infertility being less studied and diagnosed in men over time.[88] In places like Egypt,[86] Zimbabwe,[85] and Mexico,[89] erectile dysfunction, also known as impotence, is considered a determinant of infertility. When stereotypical ideals of manhood are virility and strength, men sharing problems of infertility can face feelings of inadequacy, unworthiness, and have thoughts of suicide.[90] In many cases, a variety of socio-economic interventions come in play to determine penile activity. For the Shona people, since impotence is linked to infertility, an examination to check on the penile function spans from infancy to post marriage.[85] At infancy, there are daily check-ups by the mothers on the son's erection and urine quality.[85] When the son reaches puberty, they are asked to ejaculate in river banks and for their male elders to examine sperm quality.[85] The traditions last until post-marriage, when the family of the bride take part to check on consummation and the groom's sperm quality.[85]

Crisis

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This section is an excerpt from Male infertility crisis.[edit]

The male infertility crisis is an increase in male infertility since the mid-1970s.[91] The issue attracted media attention after a 2017 meta-analysis found that sperm counts in Western countries had declined by 52.4 percent between 1973 and 2011.[92][93] The decline is particularly prevalent in Western countries such as New Zealand, Australia, Europe, and North America.[94] A 2022 meta-analysis reported that this decline extends to non-Western countries, namely those in Asia, Africa, Central America, and South America.[95] This meta-analysis also suggests that the decline in sperm counts may be accelerating.[95]

This decline in male fertility is the subject of research and debate. Proposed explanations include lifestyle factors, such as changes in diet and physical activity levels, and increased exposure to endocrine disrupting chemicals, such as those found in plastics and pesticides.[96][97] Some scientists[98][99] have questioned the extent of the crisis; the scientific community, however, generally acknowledges increasing male infertility as a men's-health issue.[100]

See also

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References

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  1. ^ Leslie, Stephen W.; Siref, Larry E.; Khan, Moien AB (2020), "Male Infertility", StatPearls, Treasure Island (FL): StatPearls Publishing, PMID 32965929, retrieved 2020-11-26
  2. ^ a b Pandruvada, Swati; Royfman, Rachel; Shah, Tariq A.; Sindhwani, Puneet; Dupree, James M.; Schon, Samantha; Avidor-Reiss, Tomer (February 2021). "Lack of trusted diagnostic tools for undetermined male infertility". Journal of Assisted Reproduction and Genetics. 38 (2): 265–276. doi:10.1007/s10815-020-02037-5. PMC 7884538. PMID 33389378.
  3. ^ "Men's Health - Male Factor Infertility". University of Utah Health Sciences Center. 2003-04-01. Archived from the original on 2007-07-04. Retrieved 2007-11-21.
  4. ^ Brugh, Victor M; Lipshultz, Larry I (March 2004). "Male factor infertility". Medical Clinics of North America. 88 (2): 367–385. doi:10.1016/S0025-7125(03)00150-0. PMID 15049583.
  5. ^ Hirsh, A. (20 September 2003). "Male subfertility". BMJ. 327 (7416): 669–672. doi:10.1136/bmj.327.7416.669. PMC 196399. PMID 14500443.
  6. ^ a b c d e f g h i j Lotti, F.; Maggi, M. (1 January 2015). "Ultrasound of the male genital tract in relation to male reproductive health". Human Reproduction Update. 21 (1): 56–83. doi:10.1093/humupd/dmu042. hdl:2158/956381. PMID 25038770.
  7. ^ Cooper, Trevor G.; Noonan, Elizabeth; von Eckardstein, Sigrid; Auger, Jacques; Baker, H.W. Gordon; Behre, Hermann M.; Haugen, Trine B.; Kruger, Thinus; Wang, Christina; Mbizvo, Michael T.; Vogelsong, Kirsten M. (1 January 2010). "World Health Organization reference values for human semen characteristics*‡". Human Reproduction Update. 16 (3): 231–245. doi:10.1093/humupd/dmp048. PMID 19934213.
  8. ^ Turner, Katerina A.; Rambhatla, Amarnath; Schon, Samantha; Agarwal, Ashok; Krawetz, Stephen A.; Dupree, James M.; Avidor-Reiss, Tomer (16 April 2020). "Male Infertility is a Women's Health Issue—Research and Clinical Evaluation of Male Infertility Is Needed". Cells. 9 (4): 990. doi:10.3390/cells9040990. PMC 7226946. PMID 32316195.
  9. ^ Kumar, M.D., Naina; Singh, M.D., Amit K; Choudhari, M.D., Ajay R (2017-08-01). "Impact of age on semen parameters in male partners of infertile couples in a rural tertiary care center of central India: A cross-sectional study". Int J Reprod Biomed. 15 (8): 497–502. doi:10.29252/ijrm.15.8.497. PMC 5653911. PMID 29082368.
  10. ^ Isiah D Harris; Carolyn Fronczak; Lauren Roth; Randall B Meacham (2011). "Fertility and the Aging Male". Reviews in Urology. 13 (4): e184–e190. PMC 3253726. PMID 22232567.
  11. ^ Nobuaki Sasano; Sadatoshi Ichijo (1969). "Vascular Patterns of the Human Testis with Special Reference to Its Senile Changes". Tohoku Journal of Experimental Medicine. 99 (3): 269–280. doi:10.1620/tjem.99.269. PMID 5363446 – via J-STAGE.
  12. ^ Forster P, Hohoff C, Dunkelmann B, Schürenkamp M, Pfeiffer H, Neuhuber F, Brinkmann B (2015). "Elevated germline mutation rate in teenage fathers". Proc R Soc B. 282 (1803): 1–6. doi:10.1098/rspb.2014.2898. PMC 4345458. PMID 25694621.
  13. ^ Forster P, Hohoff C, Dunkelmann B, Schürenkamp M, Pfeiffer H, Neuhuber F, Brinkmann B (2016). "Correction to Elevated germline mutation rate in teenage fathers". Proc R Soc B. 283 (1807): 20161723. doi:10.1098/rspb.2016.1723. PMC 5013809. PMID 27559069.
  14. ^ Rowe, Patrick J.; Comhaire, Frank H.; Hargreave, Timothy B.; Mahmoud, Ahmed M. A. (2000). "History-taking". WHO Manual for the Standardized Investigation and Diagnosis of the Infertile Male. Cambridge University Press. pp. 5–16. ISBN 978-0-521-77474-1.
  15. ^ a b Restrepo, B.; Cardona Maya, W. (October 2013). "Anticuerpos antiespermatozoides y su asociación con la fertilidad" [Antisperm antibodies and fertility association]. Actas Urológicas Españolas (in Spanish). 37 (9): 571–578. doi:10.1016/j.acuro.2012.11.003. PMID 23428233.
  16. ^ Rao, Kamini (2013-09-30). Principles & Practice of Assisted Reproductive Technology (3 Vols). JP Medical Ltd. ISBN 9789350907368.
  17. ^ Ferlin, Alberto; Arredi, Barbara; Foresta, Carlo (August 2006). "Genetic causes of male infertility". Reproductive Toxicology. 22 (2): 133–141. doi:10.1016/j.reprotox.2006.04.016. PMID 16806807.
  18. ^ Sneha, Khedkar (January 2024). "Sperm Cell Powerhouses Contain Almost No DNA". Scientific American.
  19. ^ Wu, H.; Huffman, A. M.; Whitcomb, B. W.; Josyula, S.; Labrie, S.; Tougias, E.; Rahil, T.; Sites, C. K.; Pilsner, J. R. (2018). "Sperm mitochondrial DNA measures and semen parameters among men undergoing fertility treatment". Reproductive Biomedicine Online. 38 (1): 66–75. doi:10.1016/j.rbmo.2018.10.004. PMC 6339832. PMID 30502072.
  20. ^ a b Reference, Genetics Home. "Klinefelter syndrome". Genetics Home Reference. Retrieved 2018-11-23.
  21. ^ Arai, T; Kitahara, S; Horiuchi, S; Sumi, S; Yoshida, K (January 1998). "Relationship of testicular volume to semen profiles and serum hormone concentrations in infertile Japanese males". International Journal of Fertility and Women's Medicine. 43 (1): 40–7. PMID 9532468.
  22. ^ a b Reference, Genetics Home. "Y chromosome infertility". Genetics Home Reference. Retrieved 2018-11-23.
  23. ^ Avidor-Reiss, Tomer; Khire, Atul; Fishman, Emily L.; Jo, Kyoung H. (1 April 2015). "Atypical centrioles during sexual reproduction". Frontiers in Cell and Developmental Biology. 3: 21. doi:10.3389/fcell.2015.00021. PMC 4381714. PMID 25883936.
  24. ^ Masarani, M; Wazait, H; Dinneen, M (1 November 2006). "Mumps orchitis". Journal of the Royal Society of Medicine. 99 (11): 573–575. doi:10.1177/014107680609901116. PMC 1633545. PMID 17082302.
  25. ^ Zhang, Jie; Qiu, Shu-Dong; Li, Sheng-Bin; Zhou, Dang-Xia; Tian, Hong; Huo, Yong-Wei; Ge, Ling; Zhang, Qiu-Yang (November 2007). "Novel mutations in ubiquitin-specific protease 26 gene might cause spermatogenesis impairment and male infertility". Asian Journal of Andrology. 9 (6): 809–814. doi:10.1111/j.1745-7262.2007.00305.x. PMID 17968467.
  26. ^ Cavallini, Giorgio (March 2006). "Male idiopathic oligoasthenoteratozoospermia". Asian Journal of Andrology. 8 (2): 143–157. doi:10.1111/j.1745-7262.2006.00123.x. PMID 16491265.
  27. ^ Leslie, Stephen W.; Sajjad, Hussain; Siref, Larry E. (2020), "Varicocele", StatPearls, Treasure Island (FL): StatPearls Publishing, PMID 28846314, retrieved 2020-11-26
  28. ^ Kupis, Łukasz; Artur Dobronski, Piotr; Radziszewski, Piotr (2015). "Varicocele as a source of male infertility – current treatment techniques". Central European Journal of Urology. 68 (3): 365–370. doi:10.5173/ceju.2015.642. PMC 4643713. PMID 26568883.
  29. ^ a b Teerds, K. J.; de Rooij, D. G.; Keijer, J. (1 September 2011). "Functional relationship between obesity and male reproduction: from humans to animal models". Human Reproduction Update. 17 (5): 667–683. doi:10.1093/humupd/dmr017. PMID 21546379.
  30. ^ a b Hozyasz, K (Mar 2001). "Coeliac disease and problems associated with reproduction". Ginekol Pol. 72 (3): 173–9. PMID 11398587.
  31. ^ a b Sher, KS; Jayanthi, V; Probert, CS; Stewart, CR; Mayberry, JF (1994). "Infertility, obstetric and gynaecological problems in coeliac sprue". Dig Dis. 12 (3): 186–90. doi:10.1159/000171452. PMID 7988065.
  32. ^ Freeman, HJ (Dec 2010). "Reproductive changes associated with celiac disease". World J Gastroenterol. 16 (46): 5810–4. doi:10.3748/wjg.v16.i46.5810. PMC 3001971. PMID 21155001.
  33. ^ Leibovitch, Ilan; Mor, Yoram (March 2005). "The Vicious Cycling: Bicycling Related Urogenital Disorders". European Urology. 47 (3): 277–287. doi:10.1016/j.eururo.2004.10.024. PMID 15716187.
  34. ^ Thompson J, Bannigan J (Apr 2008). "Cadmium: toxic effects on the reproductive system and the embryo". Reprod Toxicol (Review). 25 (3): 304–15. doi:10.1016/j.reprotox.2008.02.001. PMID 18367374.
  35. ^ Agarwal A, Prabakaran SA, Said TM (2005). "Prevention of Oxidative Stress Injury to Sperm". Journal of Andrology. 26 (6): 654–60. doi:10.2164/jandrol.05016. PMID 16291955.
  36. ^ Robbins WA, Elashoff DA, Xun L, Jia J, Li N, Wu G, Wei F (2005). "Effect of lifestyle exposures on sperm aneuploidy". Cytogenetic and Genome Research. 111 (3–4): 371–7. doi:10.1159/000086914. PMID 16192719. S2CID 22937424.
  37. ^ Harlev A, Agarwal A, Gunes SO, Shetty A, du Plessis SS (Dec 2015). "Smoking and Male Infertility: An Evidence-Based Review". World J Men's Health (Review). 33 (3): 143–60. doi:10.5534/wjmh.2015.33.3.143. PMC 4709430. PMID 26770934.
  38. ^ Emsley J (2001). Nature's building blocks: an A-Z guide to the elements. Oxford [Oxfordshire]: Oxford University Press. p. 76. ISBN 978-0-19-850340-8.
  39. ^ Ji G, Long Y, Zhou Y, Huang C, Gu A, Wang X (2012). "Common variants in mismatch repair genes associated with increased risk of sperm DNA damage and male infertility". BMC Med. 10 (1): 49. doi:10.1186/1741-7015-10-49. PMC 3378460. PMID 22594646.
  40. ^ Silva LF, Oliveira JB, Petersen CG, Mauri AL, Massaro FC, Cavagna M, Baruffi RL, Franco JG (2012). "Jr (2012). The effects of male age on sperm analysis by motile sperm organelle morphology examination (MSOME)". Reprod Biol Endocrinol. 10 (1): 19. doi:10.1186/1477-7827-10-19. PMC 3317862. PMID 22429861.
  41. ^ Gorczyca W, Traganos F, Jesionowska H, Darzynkiewicz Z (July 1993). "Presence of DNA strand breaks and increased sensitivity of DNA in situ to denaturation in abnormal human sperm cells: analogy to apoptosis of somatic cells". Experimental Cell Research. 207 (1): 202–5. doi:10.1006/excr.1993.1182. PMID 8391465.
  42. ^ Aston, Kenneth I.; Uren, Philip J.; Jenkins, Timothy G.; Horsager, Alan; Cairns, Bradley R.; Smith, Andrew D.; Carrell, Douglas T. (December 2015). "Aberrant sperm DNA methylation predicts male fertility status and embryo quality". Fertility and Sterility. 104 (6): 1388–1397.e5. doi:10.1016/j.fertnstert.2015.08.019. PMID 26361204.
  43. ^ Dada, Rima; Kumar, Manoj; Jesudasan, Rachel; Fernández, Jose Luis; Gosálvez, Jaime; Agarwal, Ashok (March 2012). "Epigenetics and its role in male infertility". Journal of Assisted Reproduction and Genetics. 29 (3): 213–223. doi:10.1007/s10815-012-9715-0. PMC 3288140. PMID 22290605.
  44. ^ a b Saey, Tina Hesman (6 April 2013). "From great grandma to you: Epigenetic changes reach down through the generations". Science News. 183 (7): 18–21. doi:10.1002/scin.5591830718. JSTOR 23599013.
  45. ^ Anway, Matthew D.; Cupp, Andrea S.; Uzumcu, Mehmet; Skinner, Michael K. (2005). "Epigenetic Transgenerational Actions of Endocrine Disruptors and Male Fertility". Science. 308 (5727): 1466–1469. Bibcode:2005Sci...308.1466A. doi:10.1126/science.1108190. JSTOR 3841510. PMC 11423801. PMID 15933200. S2CID 236588.
  46. ^ Hargreave TB, McGowan B, Harvey J, McParland M, Elton RA (April 1986). "Is a male infertility clinic of any use?". Br. J. Urol. 58 (2): 188–93. doi:10.1111/j.1464-410x.1986.tb09024.x. PMID 3697634.
  47. ^ Hwang K, Walters RC, Lipshultz LI (February 2011). "Contemporary concepts in the evaluation and management of male infertility". Nature Reviews Urology. 8 (2): 86–94. doi:10.1038/nrurol.2010.230. PMC 3654691. PMID 21243017.
  48. ^ "Pruebas de fertilidad en el hombre: ¿cuáles son y en qué consisten?". 9 May 2022.
  49. ^ "Pruebas de fertilidad en el hombre: ¿cuáles son y en qué consisten?". 9 May 2022.
  50. ^ Gaur DS, Talekar M, Pathak VP (2007). "Effect of cigarette smoking on semen quality of infertile men" (PDF). Singapore Medical Journal. 48 (2): 119–23. PMID 17304390.
  51. ^ a b c d Speroff L, Glass RH, Kase NG (1999). Clinical Endocrinology and Infertility (6th ed.). Lippincott Williams and Wilkins. p. 1085. ISBN 978-0-683-30379-7.
  52. ^ Salas-Huetos, Albert; Babio, Nancy; Carrell, Douglas T.; Bulló, Mònica; Salas-Salvadó, Jordi (December 2019). "Adherence to the Mediterranean diet is positively associated with sperm motility: A cross-sectional analysis". Scientific Reports. 9 (1): 3389. Bibcode:2019NatSR...9.3389S. doi:10.1038/s41598-019-39826-7. PMC 6399329. PMID 30833599.
  53. ^ Salas-Huetos, Albert; Bulló, Mònica; Salas-Salvadó, Jordi (1 July 2017). "Dietary patterns, foods and nutrients in male fertility parameters and fecundability: a systematic review of observational studies". Human Reproduction Update. 23 (4): 371–389. doi:10.1093/humupd/dmx006. PMID 28333357.
  54. ^ Agarwal, Ashok; Majzoub, Ahmad; Parekh, Neel; Henkel, Ralf (2020). "A Schematic Overview of the Current Status of Male Infertility Practice". The World Journal of Men's Health. 38 (3): 308–322. doi:10.5534/wjmh.190068. PMC 7308239. PMID 31385475.
  55. ^ Traber, Maret G.; Stevens, Jan F. (September 2011). "Vitamins C and E: Beneficial effects from a mechanistic perspective". Free Radical Biology and Medicine. 51 (5): 1000–1013. doi:10.1016/j.freeradbiomed.2011.05.017. PMC 3156342. PMID 21664268.
  56. ^ Lombardo, Francesco; Sansone, Andrea; Romanelli, Francesco; Paoli, Donatella; Gandini, Loredana; Lenzi, Andrea (September 2011). "The role of antioxidant therapy in the treatment of male infertility: an overview". Asian Journal of Andrology. 13 (5): 690–697. doi:10.1038/aja.2010.183. PMC 3739574. PMID 21685925.
  57. ^ a b Barati, Erfaneh; Nikzad, Hossein; Karimian, Mohammad (January 2020). "Oxidative stress and male infertility: current knowledge of pathophysiology and role of antioxidant therapy in disease management". Cellular and Molecular Life Sciences. 77 (1): 93–113. doi:10.1007/s00018-019-03253-8. PMC 11105059. PMID 31377843. S2CID 199436552.
  58. ^ Ghanem H, Shaeer O, El-Segini A (2010). "Combination clomiphene citrate and antioxidant therapy for idiopathic male infertility: A randomized controlled trial". Fertility and Sterility. 93 (7): 2232–5. doi:10.1016/j.fertnstert.2009.01.117. PMID 19268928.
  59. ^ de Ligny, Wiep; Smits, Roos M.; Mackenzie-Proctor, Rebecca; Jordan, Vanessa; Fleischer, Kathrin; de Bruin, Jan Peter; Showell, Marian G. (2022-05-04). "Antioxidants for male subfertility". The Cochrane Database of Systematic Reviews. 2022 (5): CD007411. doi:10.1002/14651858.CD007411.pub5. ISSN 1469-493X. PMC 9066298. PMID 35506389.
  60. ^ a b c d Edmund S. Sabanegh Jr. (20 October 2010). Male Infertility: Problems and Solutions. Springer Science & Business Media. pp. 82–83. ISBN 978-1-60761-193-6.
  61. ^ Pasqualotto FF, Fonseca GP, Pasqualotto EB (2008). "Azoospermia after treatment with clomiphene citrate in patients with oligospermia". Fertility and Sterility. 90 (5): 2014.e11–2. doi:10.1016/j.fertnstert.2008.03.036. PMID 18555230.
  62. ^ a b c d e f Rodney Rhoades; David R. Bell (2009). Medical Physiology: Principles for Clinical Medicine. Lippincott Williams & Wilkins. p. 685. ISBN 978-0-7817-6852-8.
  63. ^ Wolf-Bernhard Schill; Frank H. Comhaire; Timothy B. Hargreave (26 August 2006). Andrology for the Clinician. Springer Science & Business Media. pp. 76–. ISBN 978-3-540-33713-3.
  64. ^ Liu, Yi-Xun (January 2005). "Control of spermatogenesis in primate and prospect of male contraception". Archives of Andrology. 51 (2): 77–92. doi:10.1080/01485010490485768. PMID 15804862. S2CID 25411118.
  65. ^ Cheng, C. Yan; Wong, Elissa W.P.; Yan, Helen H.N.; Mruk, Dolores D. (February 2010). "Regulation of spermatogenesis in the microenvironment of the seminiferous epithelium: New insights and advances". Molecular and Cellular Endocrinology. 315 (1–2): 49–56. doi:10.1016/j.mce.2009.08.004. PMC 3516447. PMID 19682538.
  66. ^ Fody, EP; Walker, EM (November 1985). "Effects of drugs on the male and female reproductive systems". Annals of Clinical and Laboratory Science. 15 (6): 451–8. PMID 4062226.
  67. ^ O'Donnell, Liza; Robertson, Kirsten M.; Jones, Margaret E.; Simpson, Evan R. (1 June 2001). "Estrogen and Spermatogenesis". Endocrine Reviews. 22 (3): 289–318. doi:10.1210/edrv.22.3.0431. PMID 11399746.
  68. ^ Carreau, Serge; Bouraima-Lelong, H; Delalande, C (2012). "Role of estrogens in spermatogenesis". Frontiers in Bioscience. E4 (1): 1–11. doi:10.2741/356. PMID 22201851.
  69. ^ Sah P (1998). "Role of low-dose estrogen–testosterone combination therapy in men with oligospermia". Fertility and Sterility. 70 (4): 780–1. doi:10.1016/S0015-0282(98)00273-8. PMID 9797116.
  70. ^ Sah P (2002). "Oligospermia due to partial maturation arrest responds to low dose estrogen-testosterone combination therapy resulting in live-birth: A case report". Asian Journal of Andrology. 4 (4): 307–8. PMID 12508135.
  71. ^ Abu Elhija M, Lunenfeld E, Schlatt S, Huleihel M (2011). "Differentiation of murine male germ cells to spermatozoa in a soft agar culture system". Asian Journal of Andrology. 14 (2): 285–93. doi:10.1038/aja.2011.112. PMC 3735096. PMID 22057383.
  72. ^ James G (2012-01-03). "Sperm Grown In Laboratory In Fertility Breakthrough". Huffingtonpost.co.uk. Retrieved 2012-08-26.
  73. ^ "Scientists grow sperm in laboratory dish". Health News. London: The Daily Telegraph. 2012-01-02. Archived from the original on 2012-01-03.
  74. ^ "Researchers made Sperm Cells from Skin of infertile men". Retrieved 2014-05-08.
  75. ^ Press Association (17 August 2017). "New sperm creation method could overcome genetic male infertility – study". The Guardian. Retrieved 13 September 2017.
  76. ^ Dr. Sherman J. Silber. "A Modern Approach to Male Infertility". The Infertility Center of St. Louis. Retrieved 13 September 2017.
  77. ^ Barratt, Christopher L.R.; De Jonge, Christopher J.; Sharpe, Richard M. (7 February 2018). "'Man Up': the importance and strategy for placing male reproductive health centre stage in the political and research agenda". Human Reproduction. 33 (4). Oxford University Press: 541–545. doi:10.1093/humrep/dey020. PMC 5989613. PMID 29425298.
  78. ^ Knapton, Sarah (6 March 2018). "IVF to fix male infertility 'infringes human rights of women' argue scientists". The Telegraph. Retrieved 7 March 2018.
  79. ^ Menkveld, R.; Van Zyl, J. A.; Kotze, T. J. W.; Joubert, G. (January 1986). "Possible Changes in Male Fertility Over a 15-Year Period". Archives of Andrology. 17 (2): 143–144. doi:10.3109/01485018608990186. PMID 3827388.
  80. ^ Murature, Domingo A.; Tang, S. Y.; Steinhardt, George; Dougherty, Ralph C. (August 1987). "Phthalate esters and semen quality parameters". Biological Mass Spectrometry. 14 (8): 473–477. doi:10.1002/bms.1200140815. PMID 2957007.
  81. ^ Carlsen, E.; Giwercman, A.; Keiding, N.; Skakkebaek, N. E. (12 September 1992). "Evidence for decreasing quality of semen during past 50 years". BMJ. 305 (6854): 609–613. doi:10.1136/bmj.305.6854.609. PMC 1883354. PMID 1393072.
  82. ^ Sengupta, Pallav (2012). "Challenge of infertility: How protective the yoga therapy is?". Ancient Science of Life. 32 (1): 61–62. doi:10.4103/0257-7941.113796. PMC 3733210. PMID 23929997.
  83. ^ "Male and Female Infertility Just Keeps on 'Rising'". The New Indian Express. Archived from the original on October 23, 2016. Retrieved 2018-11-21.
  84. ^ Mukhopadhyay, Dyutiman; Varghese, Alex C.; Pal, Manisha; Banerjee, Sudip K.; Bhattacharyya, Asok K.; Sharma, Rakesh K.; Agarwal, Ashok (May 2010). "Semen quality and age-specific changes: a study between two decades on 3,729 male partners of couples with normal sperm count and attending an andrology laboratory for infertility-related problems in an Indian city". Fertility and Sterility. 93 (7): 2247–2254. doi:10.1016/j.fertnstert.2009.01.135. PMID 19328484.
  85. ^ a b c d e f Moyo, Stanzia (June 2013). "Indigenous knowledge systems and attitudes towards male infertility in Mhondoro-Ngezi, Zimbabwe". Culture, Health & Sexuality. 15 (6): 667–679. doi:10.1080/13691058.2013.779029. PMID 23550631. S2CID 5142492.
  86. ^ a b Inhorn, Marcia C. (June 2004). "Middle Eastern Masculinities in the Age of New Reproductive Technologies: Male Infertility and Stigma in Egypt and Lebanon". Medical Anthropology Quarterly. 18 (2): 162–182. doi:10.1525/maq.2004.18.2.162. PMID 15272802.
  87. ^ Serour, G.I. (1 July 2008). "Medical and socio-cultural aspects of infertility in the Middle East". ESHRE Monographs. 2008 (1): 34–41. doi:10.1093/humrep/den143.
  88. ^ Bajeux, Camille (2020-11-17). "Managing masculinities. Doctors, men, and men's partners facing male infertility in France and French-speaking Switzerland (c. 1890–1970)". NORMA. 15 (3–4): 235–250. doi:10.1080/18902138.2020.1805887. ISSN 1890-2138. S2CID 225234992.
  89. ^ Inhorn, Marcia C.; Wentzell, Emily A. (November 2011). "Embodying emergent masculinities: Men engaging with reproductive and sexual health technologies in the Middle East and Mexico". American Ethnologist. 38 (4): 801–815. doi:10.1111/j.1548-1425.2011.01338.x.
  90. ^ Smith, James F.; Walsh, Thomas J.; Shindel, Alan W.; Turek, Paul J.; Wing, Holly; Pasch, Lauri; Katz, Patricia P.; Infertility Outcomes Program Project Group (September 2009). "Sexual, Marital, and Social Impact of a Man's Perceived Infertility Diagnosis". The Journal of Sexual Medicine. 6 (9): 2505–2515. doi:10.1111/j.1743-6109.2009.01383.x. PMC 2888139. PMID 19619144.
  91. ^ McKie, Robin (2017-07-29). "The infertility crisis is beyond doubt. Now scientists must find the cause". The Guardian. Retrieved 2018-10-10.
  92. ^ Levine, Hagai; Jørgensen, Niels; Martino-Andrade, Anderson; Mendiola, Jaime; Weksler-Derri, Dan; Mindlis, Irina; Pinotti, Rachel; Swan, Shanna H (2017-07-25). "Temporal trends in sperm count: a systematic review and meta-regression analysis". Human Reproduction Update. 23 (6): 646–659. doi:10.1093/humupd/dmx022. ISSN 1355-4786. PMC 6455044. PMID 28981654.
  93. ^ Davis, Nicola (2017-07-25). "Sperm counts among western men have halved in last 40 years – study". The Guardian. Retrieved 2018-10-10.
  94. ^ Johnston, Ian (25 July 2017). "Western men's sperm counts plunge 60% in 40 years due to 'modern life'". The Independent. Retrieved 2018-10-10.
  95. ^ a b Levine, Hagai; Jørgensen, Niels; Martino-Andrade, Anderson; Mendiola, Jaime; Weksler-Derri, Dan; Jolles, Maya; Pinotti, Rachel; Swan, Shanna H. (2022-11-15). "Temporal trends in sperm count: a systematic review and meta-regression analysis of samples collected globally in the 20th and 21st centuries". Human Reproduction Update. 29 (2): 157–176. doi:10.1093/humupd/dmac035. ISSN 1460-2369. PMID 36377604.
  96. ^ Skakkebæk, Niels E.; Lindahl-Jacobsen, Rune; Levine, Hagai; Andersson, Anna-Maria; Jørgensen, Niels; Main, Katharina M.; Lidegaard, Øjvind; Priskorn, Lærke; Holmboe, Stine A.; Bräuner, Elvira V.; Almstrup, Kristian; Franca, Luiz R.; Znaor, Ariana; Kortenkamp, Andreas; Hart, Roger J. (March 2022). "Environmental factors in declining human fertility". Nature Reviews. Endocrinology. 18 (3): 139–157. doi:10.1038/s41574-021-00598-8. ISSN 1759-5037. PMID 34912078.
  97. ^ J, Whittaker (2023-02-02). "Dietary trends and the decline in male reproductive health". Hormones. 22 (2): 165–197. doi:10.1007/s42000-023-00431-z. ISSN 2520-8721. PMID 36725796.
  98. ^ Boulicault, Marion; Perret, Meg; Galka, Jonathan; Borsa, Alex; Gompers, Annika; Reiches, Meredith; Richardson, Sarah (2021-05-10). "The future of sperm: a biovariability framework for understanding global sperm count trends". Human Fertility. 25 (5): 888–902. doi:10.1080/14647273.2021.1917778. ISSN 1464-7273. PMID 33969777. S2CID 234344423.
  99. ^ "Global decline in male fertility linked to common pesticides". NBC News. 2023-11-15. Retrieved 2024-01-05.
  100. ^ De Jonge, C.; Barratt, C.L. R. (2019). "The present crisis in male reproductive health: an urgent need for a political, social, and research roadmap". Andrology. 7 (6): 762–768. doi:10.1111/andr.12673. ISSN 2047-2919. PMID 31241256.
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