In vitro fertilisation IVF-ICSI

In vitro fertilisation (IVF) with sperm microinjection is also known as ICSI (Intracytoplasmic Sperm Injection). It consists of selecting sperm and introducing it into a mature egg. It is a more laborious technique than that used in conventional IVF and requires expensive specific equipment, preparation and an experienced biologist. However, it is more effective than conventional IVF.
With ICSI, the introduction of only one sperm in each egg is guaranteed. With conventional IVF it can happen that no sperm penetrates the egg or that more than one penetrates it, resulting in a non-viable embryo.
With ICSI, a greater rate of embryos and pregnancies are obtained than with conventional IVF.

The IVF with ICSI process consists of the following stages:
a) Stimulation of egg maturation in the ovaries through daily administration of hormones. The woman can inject them under the skin herself. The time required varies and is usually around 2 to 3 weeks. During this period, progress is monitored through ultrasound scans and hormone (estradiol) testing. This data lets us know how the ovaries are responding to treatment and allow us to determine the correct day for egg extraction.

b) Egg extraction from the ovaries. This is done though puncture and aspiration of the ovarian follicles (where the eggs are located). A needle is passed through the vagina into the ovarian follicle that is going to be punctured. This is all done under visual control by ultrasound and sedation under general anaesthetic. Tracheal intubation is not necessary. The woman is under for 5-20 minutes and does not need to be admitted to the hospital; this is an entirely outpatient process.

c) Identification of the eggs. The follicle liquids extracted are observed under a microscope in the laboratory adjacent to the aspiration room in order to identify the eggs and their maturity.

If the ICSI technique (introduction of one spermatozoid into each mature egg) will be used, the eggs are stripped, that is to say, the zona pellucida that surrounds them are removed. If conventional IVF is going to be carried out, the eggs are not stripped. In our centre we practice ICSI in 100% of cases.


d) Semen preparation. This consists of isolating motile sperm from the other semen components. With the IVF technique, motile sperm is placed into the dish with the eggs in the middle of the culture (the liquid with the appropriate nutritive elements). With the ICSI technique, a single spermatozoid is introduced into each mature egg obtained.

e) Egg fertilisation observation. This is done using a microscope 16 to 20 hours after introducing the spermatozoid into the egg. If two circles can be seen, called pronuclei, this indicates that the egg is fertilised.

f) Three days after extraction of the eggs, the embryos are transferred to the uterus. This does not require anaesthetic; it is done vaginally and is eco-guided. The doctor suggests the maximum number of embryos for transfer but the woman has the final decision. The woman’s age and the couple’s medical history are taken into account. Spanish law does not allow more than three embryos to be transferred in a single cycle.

g) Assisted hatching This consists of making a hole in the zona pellucida in order to help the embryo hatch out of its protective layer and implant into the uterus At the CEFER Institute this is done in all cases.