How Sperm Washing Is Used in Intrauterine Insemination
In a traditional pregnancy, conception happens when sperm travels from the penis into the vagina, through the cervical area, and through the uterus before finally arriving in the fallopian tube, where it fertilizes an egg that has traveled from an ovary.
While this may sound like a simple matter of getting from point A to point B, the process of conceiving a child can actually be quite complicated as it relies heavily on near-perfect timing. For example, sperm have only a short period of time before they must vacate the cervical area, which can thicken, increase in acidity, and become hostile to sperm.
Intrauterine insemination [IUI] is a fertility treatment that skips this first part of the journey by placing semen directly into the woman’s uterus via a thin catheter during the time of ovulation. This procedure is often one of the first fertility treatments that couples try when they have been actively trying to conceive for a while without any success. It is also commonly performed on single women or lesbian couples using donor sperm.
However, although IUI can improve your chances of conceiving a child, placement and timing alone have their limits. To maximize the potential for success, sperm must go through a special process of preparation known as sperm washing.
How Does Sperm Washing Work?
Sperm washing is a process in which a semen sample is stripped of certain chemicals that have the potential to react adversely while in the uterus. There are a few sperm washing methods that can be performed:
Basic wash: This is a technique in which a special solution is added to the ejaculate. The semen is then put through repeated centrifugation, which separates the sperm from the seminal fluid and results in a concentrated sample of sperm cells.
Premium wash: Using a density gradient centrifugation process, motile sperm are isolated and purified, resulting in a sperm sample containing sperm with a motility of 90% or higher.
Swim-up technique: This method relies on the sperm’s own ability to self-migrate by adding a layer of media on a semen sample that encourages the most motile sperm to swim up into the media. The sperm can then be harvested.
In all three methods, a concentrated sample consisting of motile sperm is produced and can be used in the IUI procedure. This concentrated sample improves your chances of success with IUI by putting a higher number of strong sperm into the woman’s reproductive system.
Preparing for Sperm Washing
To ensure that they produce a strong working semen sample before the washing procedure, it’s crucial that men abstain from all forms of ejaculation (including masturbation) for at least two days but no more than five days. When it is time, the male deposits his specimen into a sterile container, which can be done either at home or at the fertility center.