A semen test analyses the total volume of a semen in an ejaculation sample.
Normally, semen volume is between 1.5 – 5 millilitres. If the semen volume is too low, it may not contain enough sperm, or there may not be enough secretion to nourish and help transport sperm to a woman’s egg.
Sperm count (or sperm concentration)
Sperm count (sometimes referred to as sperm concentration) measures the number of sperm in each millilitre of semen. A low sperm count may mean you will have trouble conceiving.
Sperm are programmed to swim to reach the egg released into the Fallopian tube during ovulation.
A motility test measure how active and “lively” the sperm is and whether it is following a good path to reach its “egg target”. If the sperm has poor motility, it is less able to swim towards the egg to fertilise it. If the motility rate is below 40% (i.e. less than 40 out of 100 sperm) are moving actively and in the right direction, this would suggest a male fertility issue.
The size and shape of the sperm – or its morphology - will have a bearing on fertility. Sperm which has an abnormal shape, may struggle to reach the egg (e.g. they may be less able to travel in a straight path and may move in circles instead), or will find penetration of the egg more difficult.
A morphology test examines the shape and size of sperm and specifically will look for the percentage of normal sperm in a semen sample. A morphology rate below 4% - i.e. where only 4 in 100 sperm on average look normal - would suggest a male fertility issue.