Sperm Prep for IVF
Many couples who are experiencing infertility overcome their problems with various procedures which are less invasive such as timed intercourse and intrauterine insemination – IUI. When these procedures fail to solve the infertility issues, couples often try the options available to them through today’s assisted reproductive technologies.
The progression of procedures for solving infertility leads next to in vitro fertilization – IVF. And with IVF, a range of more severe sperm and egg problems can be successfully overcome that could not be overcome with the less invasive approaches.
When a couple undergoes IVF, the eggs are retrieved and the sperm is prepared on the same day so that, later that same day, the eggs and sperm can be placed together in a small drop of culture medium in a process known as insemination. This is usually a much more effective way to achieve fertilization of eggs than IUI for several reasons. First, the sperm are processed in a way that allows for a more selective population of sperm at the end of the preparation. Also, the sperm do not have to swim a long distance to reach the egg and this selective population of sperm is located around the egg for several hours. Finally, there are usually several eggs available for fertilization during the IVF process.
Before the partner’s sperm sample can be used to inseminate the eggs during the IVF process it must be prepared so that a small population of sperm is recovered from the ejaculated semen. This preparation begins with a semen analysis of the sample, which will let the embryologist know the sperm count that is present in the ejaculated sample. The embryologist will also determine the percent of motile sperm and the percent of normally-shaped sperm in the sample. When these numbers are multiplied together, the result gives the embryologist an indication of what procedures to use in order to isolate the best possible population of sperm for insemination. The semen is then placed on a column in a centrifuge tube so that it can be filtered. This filtration isolates a small population of sperm with a much-improved percent of motility and normal morphology (shape).
After the filtration is complete, this population of sperm is washed and re-suspended in a solution that mimics the tissue fluid that is present in the Fallopian tubes of the female reproductive tract.
Before the sperm is placed with the eggs, the sperm is counted again to calculate the concentration of sperm that is needed to optimize the chance for fertilization. This population of sperm is then added to each drop of medium which contains one or two eggs.
The following morning, the embryologist will remove the embryos from the insemination drops, assess their status, and then place the fertilized embryos into fresh new drops of medium that will support their growth into a multi-celled embryo.