Intracytoplasmic Sperm Injection ICSI, which began in 1992 as a treatment for severe male factor infertility, involves the direct injection of a single sperm into each egg under direct microscopic vision.
Soon after the turn of the 20th century, it was reported that while the diagnosis of a male factor infertility had remained static, the use of ICSI had markedly increased and indications for ICSI had expanded from solely male infertility (for which it had primarily been developed) to a wide variety of other indications such as “unexplained infertility, unexplained IVF failure, Polycystic Ovarian Syndrome (PCOS) and cases where the woman’s eggs have become more resistant to conventional fertilization. ICSI was also being used in cases where sperm was absent (or virtually absent) from the ejaculate due to a congenital, traumatic, or medically acquired obstruction of the main collecting ducts (vasa deferentia), testicular failure, or in cases of traumatic, neurologic, or psychological conditions (impotency) in which no semen/sperm was being ejaculated. In such cases, sperm obtained through Testicular Sperm Extraction (TESE), or aspiration (TESA) was being successfully used for ICSI. Today, in the United States, more than 70% of all IVF fertilizations are being conducted using ICSI with high fertilization and pregnancy rates being reported, regardless of sperm concentration, motility or morphology.
Clearly ICSI is increasingly replacing conventional insemination due to its many benefits and lack of definable drawbacks. In fact, pregnancy rates achieved by this method of fertilization are at least as high as those of conventional IVF performed in cases of non-male-factor infertility. Indeed, ICSI is associated with high fertilization and pregnancy rates regardless of sperm concentration, motility or morphology.
Notwithstanding, the above, the proposition that ICSI be preferentially used as the routine method for fertilizing eggs in IVF continues to meet with resistance. Die hards argue that about 1-3% of pregnancies resulting from ICS are associated with congenital developmental and genetic defects that affect the offspring. They cite conditions such as *Beckwith-Wiedemann syndrome, *Angelman syndrome, *hypospadias, sex chromosome abnormalities, a slightly increased miscarriage rate and the fact that male offspring resulting fom ICSI pregnancies are themselves at risk of subsequently developing male infertility in later life.
What one does not often hear from nay-sayers is that the studies that cite the aforementioned risks do not distinguish cases in which ICSI was mandated for male infertility from cases in which ICSI was done for any other reasons. If this was done, in my opinion, the above mentioned birth defects and developmental conditions would be largely confined to the underlying male factor for which ICSI was indicated and not due to the ICSI process itself. In fact, a relatively recent study performed in Sweden demonstrated this well. 542 children who were conceived naturally were compared with 941 children conceived through IVF (440 by conventional IVF & 541via ICSI). The babies/children were assessed at birth and during the first 5 years of life: The findings revealed that while the incidence of birth and developmental defects was indeed higher in ICSI babies, this only applied to cases where ICSI had been done for male infertility. It did not apply to cases in which ICSI was done in the absence of male factor infertility.
Another very important consideration that supports the routine fertilization of eggs by ICSI is the fact that good quality IVF relies heavily on an ability to adequately assess egg maturation immediately following egg retrieval. To do this requires removal of layers of cumulus oophoris (CO) cells that cover the egg envelopment (zona pellucida). Only after the CO is stripped can the first polar body (PB-1) which is located immediately under the zona pellucida be identified and it is the presence of PB-1 signifies that indicates that the egg has gone through meiosis (reproductive division) and is thus mature (M2) and overwhelmingly, successful fertilization and viable embryo development requires that the fertilized egg was mature (M2). This assessment for the presence of PB-1 cannot be reliably done without first removing the cumulus oophoris cells attached to the outer surface of the zona pellucida. The problem is that stripping the cumulus oophoris cells away, markedly reduces natural fertilization potential, leaving ICSI as the only alternative by which to subsequently achieve viable embryo propagation. The only way by which to avoid fertilization by ICSI would be to bypass the important step of assessing egg maturation and this, in my opinion, would compromize IVF outcome significantly. Thus optimization of the entire IVF process virtually mandates routine ICSI in IVF.
For the above reasons, I proudly count myself among a growing majority of IVF practitioners who support the routine use of ICSI for all IVF patients
*Angelman syndrome is a complex genetic disorder characterized by delayed development, intellectual disability, speech impairment, and problems with movement and balance (ataxia). Most cases are not inherited, particularly those caused by a deletion in the maternal chromosome 15 or by paternal uniparental disomy. These genetic changes are random events that take place during the formation of reproductive cells (eggs and sperm) or in early embryonic development.
*Beckwith-Wiedemann syndrome is a congenital growth disorder that causes large body size, large organs, and other symptoms. t results from a defect in the genes on chromosome 11. About 10% of cases can be passed down through families.
*Hypospadias: Hypospadias is a condition where the opening isn’t at the tip of the penis. Instead, it is located any place along the underside of the penis.