In Vitro Fertilization (IVF) is the most widely known method in the area of Medically Assisted Reproduction and involves the fertilization of the ovum (egg) and the incubation of the embryo that are produced in laboratory conditions. The process is separated into various stages that start by investigating the existing fertility through a complete testing of both the female and the male factors as well as blood and hormonal check-up. Next comes the ovarian stimulation through medication that leads to embryo transfer, which is in fact, the completion of the procedure.
Fertilization of the oocytes is either done with the method of classic In Vitro Fertilization (conventional IVF) or with the method of Intra-Cytoplasmic Sperm Injection (ICSI)
Fertilization
- Conventional IVF
Conventional IVF is the most widely known and the first used method in the area of Medically Assisted Reproduction. That involves the co-incubation of the oocyte/s with sufficient number of specially prepared, motile spermatozoa for a period of 16-18 hours. Thus, the most progressive motile and usually normal forms of spermatozoa penetrate the zona of the oocytes, as it happens in natural conception, and fertilization occurs.
After the co-incubation period (16-18 hours) the embryologists identify the properly fertilized oocytes and the embryonic life begins, under special conditions in special designed incubations.
- ICSI ( Intracytoplasmic Sperm Injection)
ICSI is the most revolutionary method in IVF, since its accidental start in 1992 by Palermo in Brussels. With this method, millions of children have been born worldwide, from their own father genetic material, even in cases with extremely low semen parameters.
For the procedure, the oocytes after the retrieval are isolated from the surrounding cells (cumulus mass cells) and only those which are mature (Mataphase II) are forwarded for micro-insemination.
In a micromanipulation system, one spermatozoon is selected and aspirated into a special micropipette and inserted into each oocyte’s cytoplasm. The inseminated oocyte is then kept in culture conditions in an incubator and 16-18 hours later, embryologists check the evidence of two pronuclei in the cytoplasm (female and male) indicating the successful insemination technique. Further in vitro culture conditions are exactly the same as in conventional IVF.
