Embryological procedures

In vitro fertilization techniques - IVF

The traditional in vitro fertilization consists of the oocyte collection, their fertilization by the husband's or donor's sperm in vitro; the cultivation of ensuing embryos and their transfer into the uterus.
The preconditions of a successful in vitro fertilization are a normal spermiogram and at least 40% of viable sperm after 24 hour cultivation.

Micromanipulation techniques

They are laboratory techniques extending the possibilities of assisted reproduction. They can only be performed by a highly skilled personnel using very special instruments.
The essence of micromanipulation techniques is the handling of individual oocytes (eggs) and sperm or embryos under the microscope by means of special glass micropipettes.

We perform two types of micromanipulations: the intracytoplasmic sperm injection (ICSI) and assisted hatching (AH).

Intracytoplasmic sperm injection (ICSI)

The method consists in directly injecting a single sperm into the cytoplasm of a mature oocyte. The sperm selected is immobilized, aspirated into the microinjection pipette and inserted into the oocyte using a micromanipulation instrument.

The indication for use of ICSI include:

    severe oligoasthenoteratozoospermia
    failure to achieve fertilization in previous cycles
    sperm obtained by the MESA or TESE in the case of azoospermia.
    wish of patient


Assisted hatching (AH)

Assisted hatching is performed on embryos before they are transferred, whereby the embryo's membrane is carefully broken by a micropipette, which will the embryo's implantation in the endometrium. The aim of this micromanipulation method is to increase the success rate of nidation of embryos in the uterus. We recommend this method in cases of repeated unsuccessful attempts to achieve pregnancy after transfer of good quality embryos. Another indication is the patient's age of over 35.

The decision on when the micro-manipulation should be performed depends on the assessment of all the results available to date. The final decision rests with the patient.

Embryo cultivation

Traditional cultivation

Embryos resulting from a traditional cultivation are inserted into the uterus at the stage of 2 to 4 cells on Day 2 after the egg collection.

Prolonged cultivation

prolonged cultivation is a method facilitating to extend the cultivation time of fertilized eggs over the usual limit of 48 - 52 hours and it is carried out in a special medium

Extending the cultivation up to 120 hours makes it possible to monitor the embryo development longer. In this way, it is possible to reach the eight cell stage, the morula or blastocyst, and to choose the best quality embryos for the transfer. In this manner, the risk of depositing embryos with an impaired cell division capacity.

After the prolonged cultivation, embryos are transferred into a better prepared endometrium, and in this way they have got a better chance for nidation and further development.

Our results show a higher percentage of pregnancies when embryos were transfer after a prolonged cultivation.

Freezing of embryos

Cryopreservation is a process of a careful freezing of embryos. The aim is to preserve embryos resulting from extracorporeal fertilization in cases when:

    there are more quality embryos after fertilization than it is possible to transfer back to the uterus (3 embryos max)
    it has been recommended to postpone the transfer because of a laparoscopy finding indicates a risk of an extrauterine pregnancy (a surgery will be needed before unfrozen embryos can be transferred).
    the so-called hyperstimulation syndrome develops in the patient during the stimulation. In view of possible complications, it is advisable to postpone the transfer until the normal function of the ovaries is completely restored.
    there are health (inflammation, fever...) or technical problems rendering the transfer impossible
    cryopreservation is a part of the oocyte donor programme
    embryos are to be protected against radiotherapy or chemotherapy.

Pregnancy results after the transfer of frozen/unfrozen embryos are completely comparable with the results when fresh embryos are used.

How long can be frozen embryos stored?
If the patient does not get pregnant during the cycle when the embryos were frozen, the embryos will be stored for a maximum of 18 month from the day when they were frozen.
If the patient gets pregnant and delivers a baby as a result of an embryo transfer, the laboratory will automatically prolong the storage to 48 months. After that time, the storage is terminated without further notice in accordance with the Informed Consent signed by both spouses.
Storage of frozen embryos can also be terminated on basis of a request of the two spouses submitted in writing.

The period for which frozen embryos will be stored may also be extended beyond the standard limit if both spouses submit a request to this effect in writing.

How the transfer of unfrozen embryos is performed - KET
On Day 10 of the cycle, the patient comes for blood tests and ultrasound examination to Ward 16 between 7.30 and 8.30 a.m. During the aseptic ward rounds, the results of the tests will be assessed , and the doctor will then make a decision about the transfer date. All procedures connected with the transfer of unfrozen embryos are performed at our clinic.

Contacts | FAQ