ICSI involves the direct injection of a single sperm into each egg under direct microscopic vision and requires a high level of technical expertise. In fact, even when there is an absence of sperm in the ejaculate such as occurs in cases of congenital absence of the Vas deferens (when a man is born without these major sperm collecting ducts), in cases where the vasa deferentia (ducts that carry the sperm from the testicles to the penile urethra for ejaculation) are obstructed (such as follwing vasectomy or trauma), and in some cases of testicular failure or where the man has impotency, ICSI can be performed with sperm obtained through Testicular Sperm Extraction (TESE), or aspiration (TESA). In such cases, the birth rate is usually no different than when IVF is performed for indications other than male infertility.
There seems to be quite a bit of speculation about the rate of birth defects associated with children conceived through ICSI fertilization. Here are some facts:
- The performance of ICSI in cases of male factor infertility has been shown to slightly increase the risk of certain embryo chromosome deletions (leading to a slight increase in early miscarriages).
- There is some evidence that there is an increased potential for a resulting male offspring to have male infertility in later life
- There is no evidence of any significant increase in the incidence of serious birth defects attributable to the ICSI procedure itself.
- More relevant is the fact that when ICSI is performed for indications OTHER THAN male fertility issues there is NO reported increase in the risk of subsequent embryo chromosome deletions, miscarriages or in the incidence of subsequent male factor infertility in the offspring.
A relatively recent study was performed in Sweden, in which 542 children conceived naturally were compared with 941 children conceived through IVF (440 by conventional IVF & 541via ICSI). The following parameters were assessed at birth and during the first 5 years of life:
- Birth health and obstetrical complications
- Birth defects or malformations
- Family relationships
- Physical development
- Mental, psychological, and social development
No major differences in birth weight, growth, total IQ, motor development, and behavior problems or parental stress were found between the children conceived with infertility treatments and those conceived naturally.
Another major advantage of doing conventional ICSI is that it affords the opportunity to remove the complex of cells that envelop the harvested egg (cumulus) and so enable the embryologist to evaluate microscopic paramaters that point to maturity. This cannot be done with conventional IVF as the removal of these cells would virtually preclude conventional fertilization in the petri dish.
About 12-15% of conventional IVF is associated with unanticipated absent or poor fertilization. In fact new tests of sperm such as the sperm chromatin structure assay (SCSA) and the sperm DNA integrity assay (SDIA) have demonstrated that DNA damage may be present in sperm from men ith both normal and abnormal semen analyses and that male infertility is equally prevalent in such cases. Thus, disappointments associated with unanticipated failed fertilization that might be averted through routine performance of ICSI. There simply does not seem to be any practical downside to this aproach which is now routine throughout the SIRM system.
There are no data suggesting that ICSI should not be performed in all cases of in-vitro conception. In all cases, female factor or male factor (normal or abnormal spermatozoa), the use of ICSI bypasses most dysfunctions, eliminating the majority of barriers to fertilization. If fertilization does still not occur, then there is a greater chance of it being a genetic reason, and the risk of genetic abnormalities in normal spermatozoa should not be of greater concern than those in abnormal spermatozoa.
In my opinion, both the safety and scientific viewpoints strongly support the use of ICSI for all indications.
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