General Information

There are many causes of infertility and Chart 1 summarises the relative frequency of the most common ones. About 15 to 20% of couples do not become pregnant within 12 months of trying to conceive a child.  Currently around four percent of all births are the result of assisted reproductive technology (ART), including IVF, insemination therapies with donor or husband’s sperm and various surgical options.

Chart 1

Relative causes of infertility

Infertility also affects males and females in almost equal proportions, Chart 2 therefore shows a substantial number of patients will have more than one cause of their infertility and it is this multiplicity of causative factors that often makes diagnosis and treatment difficult.

Chart 2

Infertility affects males & females in equal proportions

Also of concern is the female patients’ age. Chart 3 shows how the probability of achieving pregnancy is affected by the age of the female. Peak fecundity is reached in the 20′s and this starts to decline in the early 30′s and goes onto steep decline by age 35, with the chance of pregnancy after 40 being quite low.

Chart 3

Ovarian reserve

All the eggs a woman will ever have are formed in the first weeks of life. From the start of puberty eggs are lost in every menstrual cycle until they are eventually all used up and the ovary ceases to function. This is called menopause. The use of the oral contraceptive pill does not prevent or slow this monthly egg loss. It is thought that as the woman ages the oocytes in her ovaries accumulate chromosomal defects called aneuploidies. A common aneuploidy is Downs Syndrome, which is much more common for pregnancy if the mother is 38 or older. Aneuploidies are not the only factors as the uterus also becomes less receptive to pregnancy with age. This represents a natural decline with age and there is no known way of rejuvenating either the ovary or the uterus, and age complicates any fertility treatment. This can be clearly seen in the statistics section of this web page which show a marked decline in the success with IVF over various age groups.

Charts 4 & 5 show some more common causes of infertility and how they might be treated. It must be recognized that the majority of infertility treatments do not correct the problem (if known) they merely bypass the problem. Therefore each pregnancy desired will require the same or similar treatments. Also most treatments involve the female partner even if the infertility problem lies with the male partner. This aspect of any treatment must be considered before embarking on an infertility treatment.

Chart 4

Treatments for female infertility

Chart 5

Treatments for male infertility