Advanced Sperm Quality Testing
A standard semen analysis can tell you how many sperm a man produces, how many are moving, and how many have a normal appearance under the microscope. Although a semen analysis will identify some couples with a lower chance to conceive, its overall ability to predict male fertility is poor. There is a need for better sperm quality testing. One method to test sperm quality is to look for genetic changes within the sperm. This type of sperm quality testing is known as sperm epigenetic testing.
What is inside of a sperm?
The sperm contains genetic information necessary to make a new individual. The genetic information is densely packed into the head of the sperm. The sperm contains 23 chromosomes. These 23 chromosomes will pair up with 23 chromosomes in the egg to give the 46 chromosomes necessarily for a healthy human embryo.
The chromosomes are made up of long strands of chemical known as DNA. The DNA is divided into segments known as genes. Each type of gene produces a unique protein in the cell. These proteins are responsible for performing the different functions of the cells.
Some of the genes inside of a sperm help it to do different things such as fertilize an egg or allow the embryo to develop normally. Different genes are needed to be active at different times. For example, genes #1 thru #100 might be needed to help with fertilization whereas genes #5000 thru #6000 might be needed for embryo development.
What is epigenetics?
Epigenetic modifications are changes that are made to the DNA that help the cell regulate which genes are “turned on” or activated and which genes are “turned off” or suppressed. An active gene will produce proteins. A suppressed gene will not. There are hundreds of thousands of different location in the DNA can show epigenetic changes.
Sperm quality can be tested by looking at epigenetic changes. Scientists have identified epigenetic changes in sperm that are commonly found in men with infertility or couples who seem to make poor quality embryos during IVF. The more of these “bad” epigenetic changes a man has, the greater the chance that he will have problems with infertility. Certain men are more likely to have “bad” epigenetic changes in their sperm. For example, men who smoke, are obese or are older tend to have more “bad” epigenetic changes in their sperm.
Sperm quality testing using epigenetics
One currently available test is pretty easy to do. All a man has to do is collect a semen specimen the same way he does for a routine semen analysis. The sample is sent to a special laboratory to do the testing. In a couple of weeks, the doctor will receive a report that will look something like this:
The graph show that men with infertility will often have lots of abnormal epigenetic changes. Men with normal fertility will often have few abnormal epigenetic changes.
What if the test comes back abnormal?
An abnormal test doesn’t necessarily mean that a man is unable to produce a pregnancy. It may identify men who are more likely to have problems even if their semen analysis is normal. If a lifestyle factor is identified, such as smoking, then quitting may help his fertility. In some cases, couples may choose to go directly to a more aggressive treatment such as IVF.
