Sperm Preparation for ART is necessary! When sperm is ejaculated it is surrounded by fluid (seminal fluid). A typical ejaculate contains cells, debris, dead and damaged sperm, and healthy, motile sperm. Healthy sperm is critical to the success of ART procedures and so we use sperm preparation techniques to separate functional spermatozoa for IUI, IVF, and ART and for cryopreservation. In the IVF lab there are essentially 4 techniques we use commonly; Swim-up, Swim-down, Sucrose and Ficoll-400 density gradient techniques. Each lab finds that one of these techniques will yield more motile, live and normal looking sperm for their procedures.
The density gradient sperm wash is one of the most popular sperm washing methods. This is because it also works to separate dead sperm cells, white blood cells, and other waste products from the sperm. A test tube is filled with multiple layers of liquids of different densities. Semen is then placed on the top layer of liquid and the test tube is spun in a centrifuge. After it is spun, active, healthy sperm will make their way, to the very bottom layer of the liquid in the test tube, while debris and dead sperm will get caught in the top two layers. These layers can be siphoned off, in order to remove the active sperm from the test tube.
Companies like ZyMot sell specialty devices for sperm preparation and separation that can be very expensive. The idea is that they simulate the cervical and uterine pathways that sperm must navigate to naturally fertilize an egg. By mimicking this natural selection method, sperm can be isolated without the use of chemicals or centrifugation that may damage the sperm. Instead they use microfluidic technology to isolate healthy sperm by laminar flow, which creates gradients through channels. These devices have been tested in randomized controlled trials, which is the gold standard of medical research.
ICSI was developed for men with poor sperm quality and quantity. Low sperm count, sperm motility, and abnormal morphology can be indications for ICSI. Abnormal morphology (shape of sperm) has been linked to poor fertilization. Fertilization can now be achieved for men where it previously seemed impossible. It is now used exclusively in some clinics, and it is especially important for couples who want to have their embryos genetically tested. One of the reasons why it is so widely used now, is so that the embryologists can look at the eggs and know the quality and maturation right after the egg retrieval. In conventional IVF, the egg quality and maturity is essentially a mystery because the eggs are surrounded by cells until the day after the fertilization. Fertilization rates are generally higher after ICSI compared to conventional IVF. The more embryos you have the better the chance of pregnancy!
One variation of ICSI is called “PICSI” which stands for physiological ICSI, and uses a specialized dish coated in a substance called hyaluronan. Healthy sperm are attracted to that enzyme and stick to it, they are later used to inject the egg with.
Some IVF labs may request that you and your partner collect the semen sample at home. Should patients be worried about the quality of the sample?
Originally, IVF labs insisted on “on site” collection, due to chain of custody and identification requirements. We want to see your husband/ partner face, match it to their ID, and know that the sample left their body and went straight into our own hands.
Should you be worried? It depends on the starting quality of the sperm. 99.9% of samples will be absolutely fine. In fact, once the sample makes it into the lab, it’s going to sit and “liquify” anywhere between 20 minutes to an hour or more. If male factor infertility is present, then it’s probably best to be collected in lab. For example, if retrograde ejaculation is suspected, then we need to collect all the urine AFTER the ejaculation event. Sperm are extremely hardy, and in fact they prefer a bit lower temperatures. Room temperature is perfect. Sperm are designed to withstand days in the punishing and selective vagina, cervix, and reproductive tract. The vagina first tries to kill all the sperm with acidic secretions and white blood cells. Then it sets the sperm on a race through a maze (cervix-uterus-fallopian tube), to reach the egg. In the collection cup, the sperm will be protected in the seminal fluid, and nurtured by the sugars present in it. Just follow all the lab instructions, don’t let the cup get too hot or too cold. Deliver it during the right window of time.
Data shows that up to 25% of semen specimens from men with an undetectable burden of viral RNA (HIV particles in their blood) are HIV positive. Each semen sample must be tested because those results are not consistent. HIV is detected in some samples and not others from the same man, even when HIV is not detected in the blood. SPAR stands for special program of assisted reproduction. They have developed highly sensitive techniques for sperm preparation, to detect the viral load in semen samples viruses like HIV, CMV, and Hepatitis C, and special procedures to wash the semen samples. This allows the sperm to be used for IVF to decrease or virtually eliminate the risk of transmitting the infection. These specimens can only be used for IVF, they are not appropriate for intrauterine insemination.