Rescue ICSI: Can It Save an IVF Cycle with Immature Eggs?
Rescue Intracytoplasmic Sperm Injection (Rescue ICSI) is a term that many may have encountered throughout their fertility journey. Rescue ICSI is commonly used on Day 1 AFTER an attempt of conventional fertilization from eggs retrieved.
Unfortunately, rescue ICSI does not offer a strong solution for utilizing immature eggs.
WAIT!
It really depends on our understanding of immature eggs, so stay with me now!
Understanding Rescue ICSI
Rescue ICSI is a technique employed when standard fertilization methods fail or when a significant proportion of retrieved oocytes are immature. In this procedure, sperm is directly injected into the egg's cytoplasm, bypassing natural fertilization barriers. This method is particularly considered when conventional insemination leads to suboptimal fertilization rates.
Success Rates and Outcomes
The effectiveness of Rescue ICSI varies among individuals:
Live Birth Rates: Studies have reported live birth rates ranging from 12.3% to 22.2% following Rescue ICSI procedures. For example, one study involving 307 Rescue ICSI cycles achieved a live birth rate of 22.2%.
Embryo Development: Embryos resulting from Rescue ICSI may exhibit different developmental patterns compared to those from standard fertilization methods. Some research indicates that embryos from immature oocytes fertilized via Rescue ICSI may have reduced implantation potential.
Considerations + Immature Eggs
Timing: Performing Rescue ICSI several hours after oocyte retrieval may impact oocyte quality and embryo development, potentially affecting outcomes.
Individual Factors: Success rates are influenced by various factors, including maternal age, the underlying cause of infertility, and the quality of oocytes and sperm.
Oocyte Maturity: As mentioned earlier, rescue ICSI is done after conventional fertilization fails. The reason conventional fertilization fails is that the lab is not able to check oocyte maturity before conventional fertilization. This is standard procedure in all labs because the cells surrounding the oocyte are preventing embryologists from checking maturity. The surrounding cells are REQUIRED for successful conventional fertilization. This leads to the dilemma of how we know the egg was mature and even able to be fertilized. This is where rescue ICSI is born from!
Patient Experiences
Experiences with Rescue ICSI can vary:
Some patients have reported success with this technique, leading to pregnancies and live births. For instance, a patient shared that after performing Rescue ICSI on about 10 eggs, one fertilized and was frozen, leading to a successful pregnancy in a subsequent cycle.
Others have found limited success, with some cycles not resulting in viable pregnancies despite the use of Rescue ICSI.
Does Rescue ICSI Work on Immature Eggs?
Rescue ICSI offers a potential pathway to salvage IVF cycles when conventional fertilization methods fail. Immature eggs that attempted conventional fertilization on Day 0 may have a chance for rescue ICSI on Day 1 because they matured during the 24-hour attempt of conventional fertilization. I know this can be confusing, but if you read our previous blogs, then it’ll be easier to follow!
Long story short, rescue ICSI may save your IVF cycle, with an egg matured from an immature stage AFTER the initial attempt at conventional fertilization.
“Word on the street is that kid got rescue ICSI’d”
