Egg cell vitrification What is egg cell vitrification? Thanks to recent developments, it has become possible to freeze egg cells. The technique used to do this is called vitrification. This is a method in which the freezing process occurs very rapidly. This minimizes the damage to the egg cells that results from the freezing and later thawing processes. This technique also offers new perspectives for the establishment of egg cell banks that are analogous to sperm banks. The introduction of the egg cell bank has made it possible to utilize safer and more patient-friendly stimulation schedules. Furthermore, the egg cell donor enjoys a greater degree of freedom in planning her treatment, since the timing of the preparation of the recipient does not have to be taken into account.
For whom? For women who do not yet have a partner with whom they want to have children and who - must undergo treatment that may be detrimental to their fertility, for example, chemotherapy or radiation treatments. - have an increased risk of premature menopause - want to freeze egg cells now for later use in order to get ahead of the effect of their biological clocks (egg cell quality reduces significantly with age, especially after the age of 35). For women who are undergoing IVF treatment and whose partners are unable to produce a sperm sample on the day of the ovarian puncture, resulting in the egg cells not being able to be fertilized immediately.
How many egg cells? The generally adopted rule is that 20 vitrified egg cells per patient provide a realistic chance of giving birth to a child. In other words, the chance of the birth of a child is approximately 5% per frozen egg cell. The procedure consists of the warming of the egg cells, fertilization, further division and transfer into the uterus. The number of egg cells that can be frozen depends largely on the result of the stimulation and the age of the woman.
What are the practical steps of the procedure? Before starting the procedure, you must come to the Fertility Centre for a consultation with the gynaecologist and the psychologist. During your consultation with the gynaecologist, you will receive medical information about the treatment, you will be examined clinically and your personal and family medical histories will be reviewed. A standardized questionnaire must be completed. During your consultation with the psychologist, you will go over the treatment together and situate it within a psychological and a social context. In a counselling session, various important themes will be discussed with you, such as your motivation, your expectations and your psychological resilience. The factors that you consider decisive when considering freezing egg cells and the risks associated with these are also addressed. If your fertility is reduced or you have not (yet) found a partner, then attention is also paid to learning to accept these circumstances and to
letting go of your wish for children when you get older. How can you choose between egg cell vitrification or the consideration to become a single mother? We try to guide you as comprehensibly as possible through these considerations so that you are able to make a well-thought-out decision.
What exactly is involved in the medical treatment? The most important steps in this treatment are: ď ľ stimulation of the ovaries ď ľ ovarian puncture ď ľ freezing of mature egg cells
Stimulation of the ovaries The theory The chance of success of an IVF treatment is determined in part by the number of egg cells that are obtained per treatment. To bring about the development of more than one egg cell (an average of ten), the ovaries must be stimulated. This occurs with the use of hormones (gonadotrophins), which have only a temporary effect on the body and which must be administered in the form of daily injections for a period of fourteen days. Adverse effects in the long-term are unlikely and, in any case, have not yet been determined. Usually this stimulation is combined with another type of injection which ensures that the growth of the egg cells is no longer controlled by feedback mechanisms in the body. Without the uncoupling of these mechanisms, the body would initiate ovulation at a certain moment before the ovarian punctures could be performed. The stimulation process is followed by means of ultrasonography and with blood tests, if required. This is necessary in order to be able to monitor how many egg cells develop and, more importantly, to determine the moment of their maturity and fertility.
Once the follicles have reached a diameter of approximately 20 mm, the final steps of egg cell maturation are initiated by means of a final hormone injection which also serves the purpose of preparing the uterine lining for implantation. This must occur at a specific, pre-scheduled time, because the ovarian puncture must be performed between 35 and 40 hours after the injection. The injection is usually administered in the evening between 8 pm and midnight so that the ovarian puncture can be performed one day and a half later in the morning.
The ovarian puncture (follicular aspiration, pick-up) The ovarian puncture is the only step that requires a short hospital admission of a half day. During this procedure, a fine needle is inserted by way of ultrasound control through the wall of the vagina and into the follicles. The follicular fluid containing the egg cell is then aspirated into the needle. As a rule, this occurs under a type of anaesthesia called 'conscious sedation'. This means that you will receive an anaesthetic product via a drip that is a strong pain reliever and that may make you sleepy but is not a true anaesthetic (you will still be able to react when spoken to). This is combined with the injection of a local anaesthetic at the location where the needle is inserted in the vaginal wall. General anaesthesia may be necessary in exceptional cases (for example, with difficult to reach ovaries). In these cases, the anaesthesia consists of a powerful, but short-acting narcotic administered under the supervision of an anaesthetist. Regardless of the method, the patient must remain under medical supervision for several hours to rule out any acute complications. The chance of complications, however, is very small. A small amount of blood from the follicle that is punctured is released into the abdominal cavity, which, by the way, also happens during natural ovulation. This small amount of bleeding, however, almost always stops by itself after the puncture. The point where the needle was inserted
through the wall of the vagina may also bleed somewhat after the procedure. It is very rare (risk of less than 1/1000) that an infection occurs due to the puncture procedure. If fever occurs in the days following the puncture, this must be reported to the doctor.
How to use the egg cells in the future If you would like to use the egg cells in the future, please contact us again.
After egg cell identification, the egg cells are brought to the University Hospital (UZ) in a sealed transport box. This transport box is a sealed case which is kept at a constant temperature by means of a heating element. The freezing of the egg cells also occurs there.
How can you contact us?
Dr. Tom Coetsier
Freezing of mature egg cells
Team members: Gynaecologists
Dr. Tom Coetsier
Dr. Nele Van Renterghem
Dr. Isabelle Meire
Due to their size and to the presence of a spindle apparatus (special subcellular structure), egg cells are very difficult to freeze. The recent development of vitrification has made the freezing of egg cells possible with only a minimum loss of quality. In vitrification, almost no crystals are formed, instead the egg cells take on a glass-like form. This results in less damage to the egg cells when they are warmed back up.
Storage period The storage time of vitrified egg cells is 10 years, starting from the date of freezing. After 10 years, you can send a written request via registered mail for an extension of the storage time. If you do not, the frozen material can be destroyed or used for scientific research. If you choose to request an extension, you must also state your motivation for making the request. The conditions for storage have been regulated via the relevant Act of July 2007. You can decide to terminate storage at any time.
It is best to make an appointment with the doctor and the psychologist at +32 9 224 60 92 or + 32 9 222 99 22.
Team of psychologists Psypunt
Fertility Centre AZ Sint-Lucas Groenebriel 1 – 9000 Gent tel. +329/224.60.92 – fax. +329/22406602 e-mail : Fertiliteit@azstlucas.be
Fertility Centre AZ Sint-Lucas