Intracytoplasmic Sperm Injection (ICSI)
IVF with ICSI Treatment is a procedure in which a single sperm injection takes place directly into an egg. Thus, it by-passes sperm and egg interactions involved with normal fertilization. ICSI technique is useful together with IVF to overcome severe male infertility. ICSI is a micromanipulation technique that was introduced in the early 1990’s. Since then, it’s application has been successful for the treatment of severe male infertility. To name some, suboptimal ejaculate samples, ejaculatory failure, obstructive and nonobstructive causes of azoospermia (complete absence of sperm).
Indications for ICSI:
1. Couples who have had unexplained fertilization failure in a previous IVF cycle.
2. Decreased sperm concentration, providing enough viable sperm can be recovered for injection of eggs.
3. Decreased sperm motility, including totally immotile sperm (e.g. Kartagener’s syndrome), providing sperm are viable.
4. Unusually high percentage of morphologically abnormal sperm, including round- headed sperm (globozoospermia).
5. Complete absence of sperm in the ejaculate. It can be due to an obstruction (obstructive azoospermia) caused by various conditions. The causes can be congenital absence of the vas deferens (CAVD), post-inflammatory obstruction of the epididymis or vas and failed vasectomy reversal. Fertility specialists use Testicular sperm extraction (TESE) to retrieve sperm for ICSI.
6. Complete absence of sperm in the ejaculate due to defective sperm production (non- obstructive azoospermia). Some patients may have normal sperm formation in at least some areas of the testis (identified by testicular biopsy). This can provide enough viable sperm for retrieving with TESE.
7. Ejaculatory dysfunction caused due to retrograde ejaculation (usually recovery of enough sperm from the urine) or paraplegia (electroejaculation or TESE).
8. Immunological factors; antisperm antibodies in female sera, follicular fluid or on sperm caused by vasectomy or genital tract infection.
9. Testicular cancer patients with semen samples frozen prior to treatment.
IVF With ICSI Success Rates and Risks
The ICSI procedure involves stripping cells from around the egg and injecting a needle into the egg. These procedures may damaged and degenerate (5-10%) a small percentage of eggs, often the less healthy eggs. Sometimes eggs fail to fertilize normally or arrest at an early stage of development. ICSI pregnancy rates and live birth rates are similar to those achieved with IVF. However, studies have shown that blastocyst formation is reduced compared to IVF cycles. It occurs particularly in cases of poor sperm motility and morphology. On can go with the arbitrary selection of sperm rather than relying on the natural fertilization process. Such instances has potential for increased risks of genetically abnormal embryos and birth defects including infertility.
Despite general medical acceptance by the ART community, ICSI is still a relatively new procedure. Children born as the result of ICSI are still very young and have not yet reached an age to reproduce. There are possible unknown long-term effects including those that could occur in subsequent generations.
New Findings & Reports
At this time, reports on the risk of congenital malformations associated with ICSI, compared to IVF have yielded conflicting results. A multi-center study based on data from 5-year-old children took place recently (2005). It suggests the association of ICSI with a relatively small (4.2%) increased risk of certain major congenital anomalies. There also appears to be a higher prevalence of sex chromosome abnormalities in ICSI children against those conceived with IVF (0.2% versus 1% in ICSI offspring). This can be due to the ICSI procedure itself or to an increased rate of chromosome abnormalities in sperm from some infertile men. The exact reason is not clear.
There are also some studies that report a higher incidence of a congenital malformation called hypospadias (urethra opening on underside of penis) in babies conceived through ICSI. Because some causes of male infertility are familial, and are related to genetic defects (e.g. Y-chromosome deletions) male offspring may inherit fertility problems. Therefore, patients with non-obstructive azoospermia or severe oligospermia (low sperm counts) are likely candidates for genetic causes of infertility. They should consider genetic counseling and karyotyping prior to ICSI.
In some cases, co-culture of the ICSI embryos with follicular cells collected from the follicles during the egg aspiration takes place. This provides extra nourishment and removes any embryo-toxic factors that may be present.
Fertilization Check – IVF with ICSI Treatment
What is a Fertilization Check?
A laboratory procedure performed on the day after egg retrieval. It determines which eggs have fertilized normally and can be used for embryo development and transfer.
It is important to examine the fertilized oocytes 16-20 hours after insemination to check for fertilization of oocytes (eggs). This test is important for the presence of two round nuclear structures, the male and female pronuclei (PN), formed by the sperm and egg. One must distinguish fertilized oocytes (“zygotes”) from the unfertilized and abnormally fertilized oocytes. At this point, carefully dissecting away the Cells surrounding the eggs allows clear visualization of the egg. Pronuclei must be scored within the appropriate time span, before they merge and are no longer visible (during a phase called “syngamy”). This ensures culturing or cryopreserveation of only the normal zygotes with two pronuclei (2PN’s) for embryo transfer.
Observation of abnormally fertilized oocytes takes place when eggs undergo development without fertilization (1PN) or are fertilized by two (or more) sperm (3PN). Such abnormal oocytes cannot be used for attempting to initiate a pregnancy since they are genetically abnormal.
Embryo Grading and Selection for Transfer
What is Embryo Grading?
Assigning a grade to each embryo to identify the best quality embryos. These are then selected for embryo transfer or cryopreservation.
Selection criteria or grading systems must be applied for all cleavage stages from day 2-4. It takes place to allow selection of the most viable embryos. Evaluation of embryo development takes place approximately every 24 h. Slow dividing, nondividing (arrested) or fragmenting embryos are selected. Compactin