June 2020

The Definition and Causes of Infertility

How is Infertility Defined?

As the old saying has it: it takes two to Tango. But, as regards infertility, it only takes one of the sexual partners, the male or female, to have a problem for the conceptual dance to fail. Infertility is generally defined as a failure to conceive after twelve months of regular sexual intercourse without the use of birth control. 

Worldwide, eight to twelve per cent of couples experience fertility problems, and between forty-five and fifty per cent of cases are thought to be caused by problems with the male partner. 

Causes of Male Infertility

There are a number of causes or possible causes of infertility in the male:

  • Azoospermia: this is a complete lack or very low level of sperm in a man’s semen. About one per cent of all men and ten to fifteen per cent of infertile men have a low or non-existent sperm count. Around thirty per cent of couples fail to conceive due to this problem.
  • Diminished Sperm Mobility: sperm may be sufficient in number but may not be able to ‘swim’ to their target, the egg, hence conception can be difficult.
  • Abnormal Sperm: getting pregnant can also be problematic if sperm aren’t the right shape, that is, they aren’t ‘stream-lined’ enough to swim swiftly and accurately enough.
  • Abnormal Semen: the semen itself, which carries the sperm, may be at fault, being unable to carry its load. This can be caused by a medical condition, such as cancer or a testicular infection, overheated testicles, ejaculatory disorders, or some kind of hormonal imbalance.
  • Other Causes: genetic factors, often inherited, can cause problems; abnormalities associated with the urethra, the duct in the head of the penis through which semen is ejaculated; cystic fibrosis, which can block the vas deferens the tube which transports sperm to the urethra; radiation therapy or diseases such as anaemia or diabetes. Prolonged recreational drug use can also affect male fertility.


Causes of Female Infertility

The commonest causes of infertility in women include:

  • Ovulation Problems: the inability to produce eggs, or only very few eggs, can be caused by a whole variety of factors such as a hormonal imbalance, an ovarian cyst, an eating disorder, a drug or alcohol problem, excess weight, stress, or insufficiently long menstrual cycles.
  • Damage to the Fallopian Tubes or Uterus: pelvic inflammatory disease, an infection caused by an STD, polyps in the uterus, a long-term illness, a birth defect, certain medications administered to women to avoid miscarriage such as DES (synthetic oestrogen), or endometriosis can cause serious problems with conception.
  • Abnormal Cervical Mucus: if this vital cervical excretion, which protects and ‘escorts’ the sperm on its journey through the female reproductive tract is of low quality or the wrong consistency — thick and sticky rather than thin and elastic —  the sperm’s journey to the Fallopian tubes to fertilise the egg can be more difficult. Cervical mucus can be adversely affected by stress or bad diet.
  • Drugs and Medical Treatments: non-Steroidal anti-inflammatory drugs such as aspirin or ibuprofen may cause problems with conception along with some chemotherapy drugs and radiation therapy. 

Symptoms and When To See A Doctor  

As noted above, failure to conceive after twelve months of regular ‘unprotected’ sex is the main symptom of infertility, though irregular or absent menstrual periods or evidence of hormonal problems in the man, such as changes in hair growth or difficulties with sexual functioning, may be indicators of a problem. If these or other possible indicators of infertility occur earlier than twelve months of actively trying to get pregnant a doctor should be consulted sooner. Especially if the woman is thirty-five or older, has very painful periods, has known fertility problems or has undergone treatment for cancer. Or if the man has a form of Azoospermia, a history of prostate, testicular or sexual problems, has had treatment for cancer, or has family members suffering from infertility, an immediate visit to the doctor is advisable.




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