While the factors affecting male fertility can be very varied, the key diagnostic tool is an analysis of a man’s ejaculate to assess the quality of his sperm. At The Fertility Support Company we refer individuals for sperm testing before providing acupuncture and herbal medicine along with lifestyle and nutritional advice and this test is repeated at the end of the programme so that the results are self-evident.
There are three key factors that are examined in a sperm test; the number, the shape and the movement.
1. Sperm count (oligospermia)
Although it takes only a single sperm to fertilize an egg (ovum), the odds of a single sperm reaching the egg are very low. A normal sperm count is 20 million or more sperm per millilitre of semen. In order to father a child, at least 60 percent of those sperm should have a normal shape and show normal forward movement (motility).
2. Sperm morphology
Poor morphology is one of the least predictable numbers in the semen analysis, and basically describes the percentage of sperm that look normal when examined under a microscope. The shape of a sperm is an important factor in determining how well it is able to fertilise an egg. The egg is enclosed in a protein coat called the zona pellucida (ZP) which performs many functions, the first of which is to select which sperm will fertilise the egg. The ZP bases its selection on the shape of the sperm head, so in order to pass through the ZP, the sperm must be vigorously motile and the sperm head must be a symmetrical, oval shape of the appropriate size. Sperm possessing heads that are irregular in shape, too round, too long, too big or too small are prevented from passing through the ZP.
There are two methods used to describe normal and abnormal sperm morphology; the World Health Organisation (WHO) method and the Kruger method. The Kruger method involves a more in-depth description of what determines a “normal-appearing” sperm. While the WHO method suggests that the ejaculate is viable when 40% of sperm are normal, Kruger analysis suggest that only 15% of sperm need to be defined as “normal” for successful reproduction. This discrepancy in classification has come about as the WHO classifies sperm on the borderline of normality as “normal”, whereas the Kruger system classifies them as ‘abnormal’. By classifying conservatively, the Kruger method apparently increases the chances of successfully predicting the sperm’s ability to fertilise an egg. In the 21st century, the Kruger system is used far more in modern clinics (including those used by The Fertility Support Company) to determine the feasibility of sperm.
A sperm morphology score is usually determined during the course of a semen analysis in which a microscope slide is coated with a very thin layer of semen. The slide is then stained to make the sperm clearly visible and several hundred sperm are viewed under high magnification and individually scored as “normal” or “abnormal” based on their shape. The percentage of normally shaped sperm is then calculated.
3. Sperm motility
Sperm motility scores are determined by the percentage of sperm that are moving and qualified by the sperm’s capacity to swim in a sustained, forward direction. Healthy sperm motility is the critical attribute that allows sperm to propel themselves through the uterus to the fallopian tube, penetrate the surface of the ovum, and fertilize the egg.
Sperm that show no movement (immotile sperm) may be due to structural problems in the sperm tail or be due to death of sperm (necrospermia). However, a condition known as sperm auto-immunity can also be a cause of poor sperm motility.
The immune system produces antibodies as part of the normal defence against foreign substances and organisms. Sperm are normally protected from exposure to the man’s immune system which can mistake the sperm for foreign bodies and attack them. However some men produce sperm antibodies following surgery (such as a vasectomy) or trauma to the testicles, although in other men there is no apparent cause for the development of the antibodies. The antibodies attack the sperm by attaching to the surface of the sperm and reduce their life span. As such the antibodies impair the sperm’s motility and ability to swim though a woman’s cervical mucus. Finally antibodies located on the sperm head may prevent the sperm from fertilising an egg.