ICSI – which stands for Intracytoplasmic Sperm Injection – involves the direct injection of a single sperm into each egg under direct microscopic vision. The introduction of ICSI has made it possible to fertilize eggs with sperm derived from men with the severest degrees of male infertility and in the process, to achieve pregnancy rates as high, if not higher than those that can be achieved through conventional IVF in non-male-factor cases.
With ICSI, all that is needed is a single sperm of reasonable morphologic quality. Motility is no longer a major factor in fertilization, since the sperm is carried to the egg and injected directly into it.
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 urethra for ejaculation) are obstructed (such as following vasectomy or trauma), , or where the man has impotency, ICSI can be performed with sperm obtained throughTesticular 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. The successful performance of ICSI requires a high level of technical expertise by the embryology lab.
As a general principle, if the male factor cannot be reversed in the man's body by simple medical or surgical treatment, then IVF with ICSI represents the only rational approach. Results are so high, some couples even choose this treatment mode instead of other medical or surgical treatments – even in those who are good candidates for these other treatments.
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 infertility 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.
In centers of excellence, when ICSI is employed, the IVF birth rate is unaffected by the presence and severity of male infertility. In such cases, the birth rate is usually no different than when IVF is performed for indications other than male infertility.
ICSI Success Rates
The success rate varies depending on the cause and ranges between 35-50% per cycle. No major differences in birth, behavior problems, or parental stress were found between the children conceived with infertility treatments and those conceived naturally.
IMSI or Intracytoplasmic Morphologically Selected Sperm Injection is a relatively new technique used by our fertility doctors to treat male infertility. IMSI is recommended for patients who had two or more unsuccessful ICSI attempts and for males with abnormally shaped sperm. Using this new technology enables couples to achieve higher rates of implantation and in certain cases to decrease chances of miscarriages.
Many sperm abnormalities can be identified by the embryologist using a normal microscope with magnification x400-600. This is used when ICSI treatment is performed .However, by looking at sperm using much higher magnifications ( up to x6000) coupled with a digital imaging system, it has recently become possible to identify structures within the sperm head known as vacuoles which can not be seen with a normal microscope. The presence of these sperm head vacuoles relates to an increased incidence of poor DNA arrangement within the sperm.
Recent research has shown that sperm selection using IMSI is associated with better embryo quality, higher pregnancy and lower miscarriageIMSI may be useful for the following patient groups:
- Male partners over 35 years
- Patients whereby the semen analysis has identified a high number of abnormally formed sperm
- Patients that have not achieved good quality embryos in previous cycles (if not related to egg quality)
- Patients with previous unsuccessful treatment cycles not due to an apparent egg factor
- Patients with a history of miscarriages