This method is mainly used in male infertility cases esp. after Microsurgical Sperm Retrieval Methods like Micro Epididymal Sperm Aspira (MESA), Percutaneous Epididymal Sperm Aspiration (PESA), Testicular Sperm Extraction, (TESE) etc. This could be genuinely used for lesser sperm counts (< 10 millions) or when fewer eggs are retrieved. This will help for repeated failure of IVF cases in certain conditions.
Microinjection or intracytoplasmic sperm injection (ICSI) uses micromanipulation technology to treat infertile males. A single sperm is injected into the middle of the egg (cytoplasm) for fertilization. The main advantage of this treatment is that low sperm count or abnormal sperms are not a problem. Only live sperms are needed to achieve fertilization. This avoids the need of your partner to require a donor sperm to fertilise her eggs. Thus, ICSI is one of the most common approaches towards treating male infertility. ICSI is similar to IVF except for the fertilization stage. In ICSI, the number of sperms needed may be very minimal as per the numbers of eggs retrieved. This ICSI procedure could be done for males having more number of abnormal sperms, or for elder women developing very minimal eggs.
How ICSI works
Fertility drugs are given to the wife to produce multiple eggs. These eggs are then removed using vaginal ultrasound. The cluster of cells surrounding the eggs is also removed. The husband’s sperms are collected through masturbation. Sometimes, many ejaculates are needed if the male has low sperm count. Extra sperms may be frozen for later use and thawed when needed. If the man has no sperms at all, sperm harvesting techniques are used. If his ducts are blocked or in the absence of a duct, his sperms are sucked out from the epididymis by making a hole with a fine needle. However, locating sperms in males with testicular failure can be challenging and time consuming.
Sperms are immobilized using PVP (latest being LASER immobilization) and they are aspirated singly in the microinjection needle and the egg is held using a holding pipette. Then the loaded sperm is injected into the cytoplasm of the egg. All these techniques need great deal of skill and hi-tech equipments. By doing this, several barriers of fertilization are overcome and fertilization occurs in almost all eggs injected. The overall success rates are around 43 % in day 3 transfer and 61 % success in day 5/6 transfers in our center.
Before undertaking this treatment, males are supposed to subject themselves for blood karyotyping test (DNA Analysis) which must be normal as a pre requisite for ICSI.
Surgical Sperm Extraction: This is done when there are no sperms in the ejaculate. Very few live sperms or spermatids (younger sperms) could also help in doing ICSI and getting babies. Methods explained as below are done according to the need of the male partner.
- MESA: Micro Epididymal Sperm Aspiration, using microscopic equipments and microsurgical procedures, few sperms could be extracted by this. When IVF is planned later in a convenient time, these sperms could be preserved by cryopreservation.
- PESA: Percutaneous Sperm Aspiration is done in place of MESA in few centers.
- TESA: Testicular Sperm Extraction method will extract sperms from the testes directly. Even if few Spermatids (younger sperm cells) are extracted this will serve the purpose of fertilization in ICSI procedure.
Whatever may be the mode of sperm extracted for ICSI, most of the the sperm injected eggs are fertilized (90%). When sperm morphology is poor or when the male has DNA problem, the resultant embryos are poor with lower success rates than IVF embryos.