Friday, October 30, 2009

INFERTILITY - MALE

malerepro_2

New life begins when an egg from a woman is fertilised by sperm from a man. Around 20 million sperm per millilitre (ml) need to be present in the ejaculate, with enough mobility and strength to swim the journey to the fallopian tube, where conception normally takes place. The odds of a young fertile couple conceiving by having sexual intercourse around the time of ovulation are approximately one in five every month. A couple isn’t suspected of fertility problems until they have tried, and failed, to conceive for one year. Approximately 20 per cent of couples experience difficulties. In most cases, the couple can be helped with assisted reproductive technologies. Around 40 per cent of fertility problems originate in the man. Male fertility problems include poor quality sperm or blockages in the tubes of the reproductive system.

Obstructions
Sperm are made in the testicles. During ejaculation, sperm are pushed (by muscular contractions) through a series of small tubes called the epididymis, and mixed with seminal fluid from structures called seminal vesicles. The prostate gland also adds fluid. The semen is forced along a larger tube (vas deferens), into the urethra and out of the penis. In around one in three cases of male infertility, blockages or absences of tubes (including the vas deferens) are the cause of infertility. Causes may include vasectomy and injury.

Problems with sperm

testis Problems with sperm numbers or quality are thought to be caused by genetic factors. Researchers have discovered that tiny fragments of the male chromosome may be missing in some men with sperm problems. This may cause:

  • Absent sperm (azoospermia) - the semen doesn’t contain any sperm. This may be caused by a blockage of the tubes, or testicular failure.
  • Low sperm count (oligospermia) - the ejaculate has insufficient numbers of sperm to bring about conception.
  • Abnormal shape - a healthy sperm is shaped like a streamlined tadpole. Abnormally shaped sperm may have problems penetrating the surface of the woman’s egg.
  • Poor motility - a healthy sperm has a lashing tail, which helps it to swim through the woman’s reproductive system. Sperm with poor motility may swim feebly, or not at all.
Functional problems
Functional problems that can cause or contribute to male infertility include:
  1. Impotence - the inability to get or maintain an erection sufficient for sexual intercourse.
  2. Problems with the testicles - caused by injury, infection or chemotherapy.
  3. Prostatectomy - side effects of the surgical removal of the prostate gland, including infertility, impotence and incontinence.
  4. Certain disorders - such as multiple sclerosis or diabetes can cause erection and ejaculation difficulties.
  5. Antibodies - the man’s immune system makes antibodies that hinder the activity of sperm, such as reducing the sperm’s ability to latch onto the partner’s egg.

Hormonal problems
The levels of male sex hormones are regulated by a series of glands and their hormones. The pituitary gland in the brain influences hormone production in the testicles, under the guidance of another brain structure - the hypothalamus. A relatively uncommon cause of male infertility is the failure to make enough of the hormone gonadotrophin.

Idiopathic infertility
For around one in 10 couples investigated for infertility, no cause is found. This is called ‘unexplained’ or ‘idiopathic’ infertility.

Diagnosis methods
Investigating suspected infertility requires a number of tests for both the man and his partner. Diagnosing male infertility may involve:

  1. Semen analysis - a sample of the man’s semen is investigated in the laboratory and checked for abnormalities and the presence of antibodies.
  2. Blood tests - to assess hormone levels.
  3. Testicular biopsy - a fine needle and microscope are used to check the network of tubes to see if there are any sperm in them.
  4. Ultrasound test - to take pictures of the reproductive organs, such as the prostate gland.
Treatment options
There are no treatments available that can improve the quality of a man’s sperm. However, techniques can increase the odds of conception using the existing sperm quality. Treatment depends on the cause, but may include:
  1. Hormone therapy - if low sperm count is due to insufficient levels of the hormone gonadotrophin.
  2. Artificial insemination - the semen is collected and concentrated, then delivered with instruments directly into the partner’s uterus.
  3. In vitro fertilisation - conception occurs in the laboratory and the fertilised egg is implanted in the prepared uterus.
Things to remember
  • Around 40 per cent of fertility problems originate in the man.
  • Male fertility problems include poor quality sperm, low sperm count or blockages in the tubes of the reproductive system.
  • Treatment options for poor sperm quality include artificially inseminating the partner with a concentrated sample of the man’s semen.

0 comments:

Post a Comment