Male Factor - Cryptozoospermia
We identify a problem with the sperm in about 30% of couples having infertility treatment. The issues range from having a low sperm count or motility, to having no sperm at all, or even to having sperm that are incapable of fertilizing eggs without significant intervention. The vast majority of these sperm problems can be solved by injecting a single sperm into each egg, using a technique called Intra Cytoplasmic Sperm Injection (ICSI). This works well for sperm with limitations such as poor motility or abnormal morphology (size and shape), and ICSI can be used in conjunction with chemical treatment of the egg in conditions such as gloobozoospermia (round headed sperm) where the sperm need a little help to complete the fertilization process. We also work with a lot of patients that do not ejaculate sperm and perform minor surgeries to retrieve sperm form the testicle or epididymis. As embryologists we prefer sperm from the epididymis over testicular sperm since these sperm are more mature and closer to the end of the development process. But we work with whatever sperm we can get, and sometimes getting just a few sperm can be a real challenge.
Concentrating the semen sample to a small volume has some drawbacks, as all cells and debris will end up in the concentrate. Naturally, semen contains many other cells besides sperm, such as white blood cells, sperm precursor cells and epithelial cells from the reproductive tract that are shed into the ejaculate. Sperm and other cells that are dying, dead or disintegrating are also present, so the concentrated semen sample can be viscous and “dirty”. The embryologist is not trying to find sperm in a clear fluid, but rather in a pool of other cells and debris, and DNA that leaks from dead cells can make the drops sticky and hard to work with. So we are careful to concentrate the sample enough to reduce the volume we have to search through, but not so much that the sample is too thick to work with.
The drops are usually around 5 microliter (µl) in size, so a sample concentrated to ½ milliliter (ml) would give us 100 drops to search through. If the patient gives us a second sample, the same processing is performed and the same number of drops would be created for searching. Often, these patients give us samples on 2-3 successive days leading up to their partner’s egg retrieval procedure, in the hope that we will be able to accumulate enough sperm to inject all her eggs. In the worst cases, the couple might have donor sperm available (from a relative or an anonymous sperm donor) in case we fall short. When a sperm is found, it is picked up in a sterile glass needle and moved to a holding drop of fresh culture medium, hopefully joining other sperm that have already been collected that day, or in previous days. And when we finally sit down to inject the eggs, there’s a great sense of achievement all around due to the sheer time and effort given to the sperm hunt. All of our babies are special, but for our patients with cryptozoospermia, there’s a really amazing sense of achievement among the embryologists for each pregnancy. Only we really know the tremendous effort that was needed to create that life.
- Joe Conaghan, PhD
PFC Lab Director