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ICSI: Who it's For and How it Works
For couples who end up needing In Vitro Fertilization (IVF) in order to conceive, learning about the process can be overwhelming. There are preparations, medications, costs, injections, tests to learn about - a whole new world of procedural aspects and terminology you probably wouldn't have otherwise known about. For many couples, one component of their IVF plan-of-attack they may need to familiarize themselves with is ICSI.
ICSI (short for intracytoplasmic sperm injection) is a fertilization technique that was developed more than twenty years ago, to best bypass certain issues with sperm and/or fertilization during an IVF cycle.
In any fresh IVF cycle, the female's eggs are retrieved and incubated to prepare for fertilization. In a conventional cycle without ICSI, multiple sperm are put into a petri dish with the egg, where they will compete and if all goes well, one will naturally fertilize. With ICSI, before fertilization the semen is spun in a machine called a centrifuge to weed out the healthier prospects from dead sperm and normal debris. The embryologist then chooses a single live sperm to inject directly into the egg using a small, special needle.
So who does ICSI benefit, and how does it benefit them?
Dr. Christo Zouves, a Reproductive Endocrinologist and Medical Director of Zouves Fertility Center in Foster City, CA, explains that it's not just for male factor infertility, but for unexplained infertility.
"ICSI was developed to treat severe male factor infertility but it is also used to ensure fertilization with a diagnosis of unexplained infertility," He explains."It is also recommended when comprehensive chromosomal screening is planned on embryos. Some programs do ICSI in 100% of IVF cases because there may sometimes be low or no fertilization when no sperm factor was suspected."
Long before a couple going through IVF does their very first injection, chances are they have done their research and meticulously planned the details as much as possible. Without a diagnosis hinting otherwise, a previous failed IVF cycle or any indicator that there is an issue with sperm, patients go into an IVF cycle assuming that they will get good fertilization, high quality embryos to put back and hopefully some leftover to freeze. It's safe to say that when a couple has reached the IVF stage in their treatment, the last thing that they want is any kind of surprise during their cycle.
With that in mind, does ICSI do anything to increase the fertilization in an IVF cycle? Could it even increase the fertilization chances in what would have otherwise been a good rate to begin with?
"ICSI does not give better than good fertilization which is approximately 70%," says Dr. Zouves, "but it does prevent low or no fertilization which could mean loss of a whole IVF cycle."
Some patients may be more comfortable - either to avoid a little additional cost or to keep the process as close to 'natural' as it can be - letting sperm naturally compete if there's no suspicion that they should do otherwise. On the other hand, ICSI is something worth considering even if all evidence points to natural fertilization working, if for no other reason than to lessen the chance of a surprise fertilization report. If you can't quite decide between the two, is it possible to do both?
"Some clinics recommend doing “split ICSI” where half the eggs are mixed with prepared sperm and the other half are injected directly," Dr. Zouves explains, but he also adds "Personally, I would recommend doing
ICSI on all eggs retrieved, unless there was confirmation of prior normal fertilization in which case I would recommend no ICSI but just mixing of egg and sperm. I do not recommend “split ICSI”."
ICSI is most often used to combat forms of severe male factor infertility - such as low sperm count, low motility, and/or poor morphology. It is something, however, to consider for any IVF cycle.