Long-Term Complications of ICSI: Genetics
What is ICSI?
Intracytoplasmic Sperm Injection (ICSI) is a common Assisted Reproductive Technique (ART) that is usually recommended to couples undergoing Fertility Treatments. It is usually recommended over In-Vitro-Fertilization (IVF) when Male-Factor Infertility is present, meaning that there may be an issue in the quality of sperm (motility, quantity, morphology, etc.).
How popular is the use of ICSI?
The use of ICSI has continued to grow over the last decade, it has become more and more popular. In the United States the use of ICSI doubled from 36.4% to 76.2% of all ART procedures performed from 2006 to 2012. More couples will choose to use ICSI over IVF when IVF has already been attempted (sometimes various times), with the hope that it will increase their chances of conception.
How does it work?
The dilemma with ICSI (as opposed to IVF) is that it removes the process of natural selection for spermatozoa. When millions of the little sperm cells compete to fertilize an egg, the sperm cells of lower quality may not have the ability to actually penetrate the egg, or may be unable to move effectively to actually reach the egg, and as a result will not end up fertilizing the egg. Instead, the sperm cell that is healthy, has good motility, and can enzymatically breakdown the protective coat of the egg and penetrate it will have a much higher probability of doing so. ICSI eliminates this selection process, and instead a single pre-selected sperm cell is injected in to the egg.
However, research studying the benefits of ICSI has not shown any promising improvement in pregnancy or live-birth rates when compared to IVF for non-male factor infertility. The success rates of ICSI are similar to those of IVF.
Long-Term Risks Associated with ICSI
One thing ICSI has been shown to increase is genetic birth defects. A recent review found about 2.5% of IVF transfers and 3.0% of ICSI procedures had genetic abnormalities. The first impression is that the amount of increased risk is rather small, but when we think about how many ARTs are taking place in a year, that 0.5% can translate to thousands of lives. One key thing to mention here is that, it is not clear whether this increased risk is directly a result of ICSI or because it is being used in couples where the sperm quality is already lower.
Another concern raised by researchers was the increased likelihood of damaging the meiotic spindle (kind of like the skeleton of the egg) during the injection procedure.
The Practise Committees of the American Society for Reproductive Medicine and the Society for Reproductive Technology state that there is no evidence for the use of ICSI for non-male factor infertility. Considering that there may be increased risks associated with ICSI when compared to IVF, but lack of clear evidence for any additional benefit, it makes sense. However, the use of ICSI in non-male factor infertility has increased by approximately 6% from 2006-2010.
Another consideration is cost. The cost of choosing ICSI over IVF is estimated to be about an additional $2500 - $3000 USD in the United States.
Some of the genetic risks associated with ICSI have been reported to be the following: angleman syndrome, weidemann syndrome, and decreased cognitive and psychomotor development.
What about Male-Factor Infertility?
The recommendation is to still use ICSI when facing male-factor infertility, as it is still advantageous when sperm are unable to penetrate the egg on their own.
The bottom line is this: ARTs are still relatively new technologies, and as new research continues to come out recommendations may change. But it is important to make sure you are making an informed decision and understand where the current evaluation stands. Each case of infertility is unique, and at the end of the day, the decision about which ART to use is between you and your Doctor. The most important thing is that the decision about which ART you will end up using is the result of a healthy conversation between you and your doctor.
Xiong, X., Dickey, R. P., Buekens, P., Shaffer, J. G., & Pridjian, G. (2017). Use of Intracytoplasmic Sperm Injection and Birth Outcomes in Women Conceiving through In Vitro Fertilization. Paediatric and Perinatal Epidemiology. doi:10.1111/ppe.12339