Approximately 40% of infertility is related to the male. Key to understanding male fertility is analysis of the semen. Semen samples can vary from month to month, or even day to day because it takes about 72 days for sperm to develop within the testicles. Unlike eggs, which are present since you were born, sperm are made all the time following puberty. Since men are producing sperm all of the time and since illnesses, injuries, medications, or illicit drug use a few months before could make one sample abnormal, a repeat semen analysis three weeks later should be done.
Sometimes a semen analysis shows a low number of sperm which is less than 20 million and is called oligospermia. If no sperm are found , it’s called azoospermia. When sperm do not swim very well, this condition is called asthenospermia. Sometimes there are a lot of moving sperm, but the sperm themselves look abnormal. Abnormal sperm morphology (what the sperm look like) is the most sensitive indicator of whether a man will get their partner pregnant the old fashion way. In spite of their small size, sperm have three distinct regions: the head, neck or mid-piece, and tail. An abnormality in any of these sections can cause infertility. The head of the sperm contains the genetic material (DNA) needed to make a baby. If the head is abnormally shaped, fertilization may be impaired and if fertilization is able to occur, an abnormal embryo may result not capable of implantation or making a baby. The mid-piece of the sperm contains the energy producing organelles enabling the sperm to get to an egg and the tail of the sperm makes the sperm move rapidly through the maze of the female reproductive tract.
There are two ways of determining sperm morphology: an out-dated method using criteria established by the World Health Organization (WHO) in the 1970’s and is still used in most hospitals and path-labs; and Kruger morphology using ‘strict criteria’ which is used by the best fertility centers. Studies using ‘strict criteria’ morphology assessment have been correlated with fertilization in IVF. Men with greater than 14% normal appearing sperm had normal fertilization rates, while men with intermediate morphology (between 4-14%) had intermediate fertilization. Men with less than 4% normal looking sperm had only an 8% chance of achieving fertilization using standard insemination techniques (one egg per 10,000 sperm). Less than 4% normal morphology is called teratospermia. Successful pregnancies can be achieved especially when using IVF together with Intracytoplasmic Sperm Injection or ICSI. This is when one sperm is injected per egg using a microscopic techniques.
The identification of sperm morphology using Kruger’s ‘strict criteria’ is an integral part of the semen analysis and hence the most important part of the evaluation of male fertility. So make sure that your physician uses this test when doing a semen analysis. In this way the most likely treatment to help you have a baby can be done.