In Vitro fertilisation with intracytoplasmic sperm injection (VIF-ICSI)
This procedure is called ICSI from English and stands for Intracytoplasmic Sperm Injection. It consists of the insemination of each egg via the injection of a single sperm inside its cytoplasm. .
ICSI is carried out together with IVF. The steps before and after the insemination are exactly the same (ovarian stimulation, egg collection and embryo transfer), the only difference is the insemination procedure. Employing this technique less sperm is needed, as only one per egg is required, whereas with IVF 50.000 to 100.000 sperm are necessary. There have been remarkable advances in the treatment of male sterility since the application of ICSI.
ICSI procedure
First step (ovulation stimulation and monitoring) In order to obtain the eggs the ovulation has to be stimulated with fertility drugs. The follicle stimulating hormone (FSH) will be administered to the woman as well as GnRh antagonists. A strict control of the menstrual cycle monitoring the Estradiol (a hormone) level in the blood, and an ultrasound of the follicular development in the ovaries is carried out. When the hormone levels and the number and size of the follicles are sufficient, their maturity is triggered by use of a hormone called LH (luteinizing hormone).
Second step (IVF) 36 hours after administrating the LH, the gynaecologist collects the eggs. This procedure consists of puncturing the follicles by means of a vaginal ultrasound and liquid aspiration on the inside. This liquid is taken to the laboratory where the biologist separates the eggs from the liquid. The eggs are cultivated in culture medium while the sperm is prepared (as with Artificial Insemination). Later on the biologist carries out the insemination which consists of injecting a single sperm into an egg.
With ICSI a sperm has to be selected and injected into the cytoplasm of an egg. A micromanipulator connected to a microscope is used in order to carry out this procedure. The insemination has to be done with all eggs available. The following day a check is made on how many eggs have been fertilised.
Third step (transfer) Two or three days later the fertilised eggs (or zygotes) start dividing and become embryos which are ready to be transferred to the uterus. Two or three embryos are selected for the transfer. They are introduced in the uterus together with a small quantity of culture medium in a fine catheter. Under an abdominal ultrasound control, the gynaecologist places the catheter up to the end of the uterus where the embryos are deposited.
Fourth step (cryopreservation) The non transferred embryos are frozen in liquid nitrogen (cryopreservation) and stored correctly identified in the embryo bank of the laboratory. These embryos can be used in future cycles if pregnancy does not occur at the first attempt. Obviously, it simplifies the process and makes it cheaper, although the pregnancy rates decrease.
This technique is recommended in...
Insemination using ICSI began in 1992 and was first used in cases of male sterility due to unknown causes or when IVF was not viable. For example, when there is a very small number of spermatozoa in sperm (severe oligozoospermia) or when sperm motility is very low (severe astenozoospermia).
Special cases
When there are no motile sperm in the ejaculate they can be obtained via epididymis aspiration or via a biopsy of the testicular tissue. This technique is used when the man wants to have a child had a vasectomy (a sufficient semen sample cannot be obtained by means of a deferent duct puncture) or in special cases such as malformation of deferent ducts, retrograde ejaculation, paraplegia, tetraplegia and impotence. The possibilities for the fertilisation and development of normal embryos with testicular sperm are identical as with ejaculated sperm, and the process is exactly the same.