The breakthrough of intracytoplasmic sperm injection or ICSI back in the early 1990s has made it possible to fertilize eggs with sperm derived from men with male factor infertility.
ICSI involves the direct injection of a single sperm into each egg under direct microscopic vision and requires a high level of technical expertise. It can also be performed for men following testicular sperm extraction or aspiration (TESE and TESA respectively) when there is absence of sperm in the ejaculate when the vas deferens is missing (when a man is born without these major sperm collecting ducts). This also applies to cases where the vasa deferentia (ducts that carry the sperm from the testicles to the urethra for ejaculation) may be obstructed, possibly due to vasectomy or previous trauma, and also in some cases of testicular failure or where ejaculation may not be possible.
ICSI was developed for use in male factor infertility, and when used in this, what studies have demonstrated that has raised worries for many patients, is that there is a small increase in the number of chromosomal abnormalities in the resulting embryo, which may be responsible for an increased risk of miscarriage, birth defects (Davies et al 2012) and there is also a potential observed increase that any male children born this way may themselves potentially suffer from male infertility. But, and here is the controversial bit, some people believe that ICSI should be done in all cases, not just in the presence of male factor infertility, because of the superior fertilization rate, and because when ICSI is done to treat subfertile couples, but NOT male factor infertility, none of the above increases in genetic abnormalities are observed.
Therefore, it would seem logical to perhaps conclude, although this isn’t yet possible to prove, that any potential complications caused by ICSI are likely due to the indication for which ICSI is being done, ie male factor infertility, rather than the technique itself. Meaning that men who have suboptimal sperm are potentially more likely to create genetically abnormal embryos that may either result in miscarriage, congenital abnormalities or be affected by male factor infertility themselves in the future. Giving even greater reason to try and correct some of the sperm abnormalities through diet and limiting exposure to external toxins, but more on that in another blog.
Now because of the above, some experts believe that ICSI should be used in all patients who need fertility treatment. But, if you look at some of the data, as emerged from the Battacharya study in the Lancet 2001, it appears that when ICSI is done for non male factor infertility, the implantation and clinical pregnancy rates are higher in the group that had IVF, compared to ICSI. Also, when data from studies around the world is collected on this, it shows that livebirth rates are lower in those countries where ICSI is used far more often than IVF, such as in Italy and Belgium.
Having said that, there are some studies showing that ICSI may be better in some groups of patients, even when there is no male factor infertility, such as perhaps those women with low ovarian reserves, where ICSI has been shown to improve fertilization rates, but not necessarily livebirth rates (Butts et al 2014). Also using ICSI in those with previous failed rounds of fertilization with IVF, or when fertilizing eggs that had previously been frozen, or indeed, using frozen sperm. In addition, when doing pregenetic screening (PGS), the egg requires its surrounding cells to be removed, making it less likely to be fertilized by IVF, meaning ICSI becomes necessary. Importantly, some experts feel that ICSI may also have a role in unexplained infertility, as they suggest that our current testing techniques for semen may not detect some of the more subtle male factors, that could be responsible for why the couple is not getting pregnant. In fact, newer tests of sperm function such as the sperm chromatin structure assay, have shown that DNA damage may be present in sperm derived from men with both normal and abnormal semen analyses.
So, in summary, there are some universally accepted reasons for doing ICSI, but what experts don’t necessarily agree on is when to do ICSI in the absence of male factor infertility. More research is needed in this, and if you have any concerns or issues regarding your case, please always seek the opinion of a fertility specialist.