Male infertility refers to the inability of a male to achieve a pregnancy in a fertile female. In humans it accounts for 40-50% of infertility.^[1][2][3] Male infertility is commonly due to deficiencies in the semen and semen quality is used as a surrogate measure of male fecundity.^[4]

[edit] Causes

Factors relating to male infertility include^[5]:

[edit] Pre-testicular causes

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:

• Hypogonadism due to various causes
• Drugs, alcohol, smoking
• Strenuous riding (bicycle riding,^[6] horseback riding)
• Medications, including those that affect spermatogenesis such as chemotherapy, anabolic steroids, cimetidine, spironolactone; those that decrease FSH levels such as phenytoin; those that decrease sperm motility such as sulfasalazine and nitrofurantoin.

[edit] Testicular factors

Testicular factors refer to conditions where the testes produces semen of low quantity and/or poor quality despite adequate hormonal support and include:

• Age
• Genetic defects on the Y chromosome
  • Y chromosome microdeletions
• Abnormal set of chromosomes
  • Klinefelter syndrome
• Neoplasm, e.g. seminoma
• Idiopathic failure
• Cryptorchidism
• Varicocele (14% in one study)^[7][8]
• Trauma
• Hydrocele
• Mumps^[9]
• Malaria
• Testicular dysgenesis syndrome
• Defects in USP26 in some cases^[10]
• Acrosomal defects affecting egg penetration
• Idiopathic oligospermia - unexplained sperm deficiencies account for 30 % of male infertility.^[11]

[edit] Post-testicular causes

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:

• Vas deferens obstruction
• Lack of Vas deferens, often related to genetic markers for Cystic Fibrosis
• Infection, e.g. prostatitis
• Anti-sperm antibodies
• Retrograde ejaculation
• Ejaculatory duct obstruction
• Hypospadias
• Impotence

[edit] Diagnosis

The diagnosis of infertility begins with a medical history and physical exam by a physician, preferably a specialist with experience or who specializes in male infertility. Typically two separate semen analyses will be required. The provider may order blood tests to look for hormone imbalances, medical conditions, or genetic issues.

[edit] Medical history

The cornerstone of the male partner evaluation is the history. It should note the duration of infertility, earlier pregnancies with present or past partners, and whether there was previous difficulty with conception.

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, 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.

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).

A family history may reveal genetic problems.

[edit] Physical examination

A complete examination of the infertile male is important to identify general health issues associated with infertility. For example, the patient should be adequately virilized; signs of decreased body hair or gynecomastia may suggest androgen deficiency.

Usually, the patient disrobes completely and puts on a gown. The physician will perform a thorough examination of the penis, scrotum, testicles, anus and rectum.

The scrotal contents should be carefully palpated with the patient standing. As it is often psychologically and physically uncomfortable for men to be examined, one helpful hint is to make the examination as efficient and as matter of fact as possible.

The peritesticular area should also be examined. Irregularities of the epididymis, located posterior-lateral to the testis, include induration, tenderness, or cysts.

[edit] Sperm sample

The volume of the semen sample, approximate number of total sperm cells, sperm motility/forward progression, and % of sperm with normal morphology are measured. This is the most common type of fertility testing^[12]. 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

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.

[edit] Blood sample

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.

[edit] Prevention

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

• Avoiding smoking^[13] as it damages sperm DNA
• Avoiding heavy marijuana and alcohol use.^[14]
• Avoiding excessive heat to the testes.^[14]
• Sperm counts can be depressed by daily coital activity^[14] and sperm motility may be depressed by coital activity that takes place too infrequently (abstinence 10-14 days or more).^[14]

[edit] Treatment

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

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.

The off-label use of Clomiphene citrate, an anti-estrogen drug designed as a fertility medicine for women, is controversial.^[15] Vitamin E helps counter oxidative stress, which is associated with sperm DNA damage and reduced sperm motility.^{[citation needed]} A hormone-antioxidant combination may improve sperm count and motility.^[16]

[edit] See also

• Fertility preservation

[edit] References