Fertility disorders are incredibly common: it is estimated that between 10 and 15% of couples experience problems conceiving. Falling pregnant actually involves a great deal of chance. The probability of a healthy fertile couple becoming pregnant is around 25% a month, but decreases, as a woman gets older. For couples with reduced fertility, the monthly probability is smaller. Reduced fertility is referred to as “subfertility” in medical jargon. (The term infertility is reserved for couples for whom there is no chance of a spontaneous pregnancy.)

A distinction is drawn between couples who have never achieved a pregnancy together (so called “primary” subfertility), and couples who have previously conceived together but have not succeeded subsequently (“secondary” subfertility). Secondary subfertility includes couples with one or more children as well as couples who have experienced a past miscarriage.

• For women younger than 35, subfertility is defined as the lack of conception over a period of 12 months or more during which unprotected intercourse has occurred. For women over the age of 35 years, the time period used to define subfertility is reduced to six months.
  
• Women who experience irregular menstruation or periods - which may point to problems with ovulation (egg release) - are generally advised to consider evaluation and treatment earlier.
  
• In general reduced fertility occurs in approximately 1 in 6 couples.
  
• Reduced fertility is not more common in people of a specific race or ethnic origin.
  
• The term infertility is actually reserved for couples for whom there is no chance of a spontaneous pregnancy.

• Couples with normal fertility have an 85% chance of becoming pregnant in the course of one year. For approximately 1 in 12 couples, becoming pregnant can take longer than 2 years.
  
• Infertility occurs at about the same frequency in men and women. As a rule of thumb, in approximately 30% of cases, the problem can be traced back to the woman, while in 30% it can be traced back to the man. In another 30%, a combination of problems exists in both partners, while approximately 10% of couples fail to display any identifiable problems that could explain their reduced fertility.
  
• The age of a woman is one of the most important predictors of fertility. While many women become pregant after their thirtieth birthday, a women is actually at her most fertile in her mid twenties. Thereafter, fertility diminishes gradually up to the age of thirty and then decreases rapidly throughout the thirties. The most common female fertility problem is a problem with ovulation (egg release).
  
• The probability of a woman of 35 years becoming pregnant is approximately half that of a woman of 20 years, but drops to 10% for a woman of 40.
  
• A 37 year-old woman has approximately a 25% chance of experiencing a fertility problem; a woman of 41 years, 50%, and a woman of 43 years, a 75% chance of having a fertility problem.
  
• For men, fertility diminishes slowly until around the age of 40, after which it begins to decrease more rapidly. The most common causes of male infertility are reductions in the number or mobility of sperm cells and/or changes in their shape.

• The procedures described as assisted reproductive technologies (ART) include in vitro fertilisation (IVF) and related procedures.
  
• Such procedures are absolutely essential for some couples in whom conventional therapies have been unsuccessful.

Treatment depends on identifying the underlying cause of the reduced fertility. Thereafter, a range of different options is available, which can be grouped under the following headings.

• Natural treatment which involves the use of drugs only, for example, ovulation induction (OI).
  
• Assisted treatment which involves the use of drugs as well as a fertility stimulating treatment (such as intra-uterine insemination or IUI).
  
• Assisted reproduction which involves the use of drugs combined with an ART technique through which “test tube” fertilisation occurs such as IVF or Intracytoplasmic Sperm Injection (ICSI).
  
• In some cases, surgical intervention may be necessary to increase the chances of a potential pregnancy. One of the above treatments is often still necessary thereafter.
  
• One recent possibility that has become available for some couples, especially those affected by male infertility, is a technique called Intracytoplasmic Sperm Injection (ICSI). Instead of combining “normal” ova (egg) and sperm cells in a Petri dish for standard IVF, this fertilisation technique involves the injection of a single sperm cell into the ovum. The use of ICSI has spectacularly improved the fertilisation rate in cases of insufficient or insufficiently mobile sperm or poor sperm function. This method was first described in 1992.
  
• In the rare instances when there is a complete absence of sperm cells in the semen (azoospermia) due to a blockage of the sperm ducts, attempts can be made to obtain sperm cells directly from the epididymis. This takes place through a puncture or tapping (withdrawing the material with a needle). The retrieved sperm cells can then be used for a standard ICSI procedure. This technique is known as PESA - ICSI.