After the ovarian stimulation has been completed and the ovaries have reached the final stage of maturation, egg retrieval is being scheduled. Egg retrieval takes place at the operating room, in a sterile environment, with the administration of light sedation (conscious sedation) by the anesthesiologist. The woman arrives one hour before egg retrieval, fasting the night before and has not used any perfume. Prior to egg retrieval, she will undergo a heart examination and a cardiogram
Egg retrieval is performed by transvaginal puncture and aspiration of the follicles under continuous ultrasound monitoring and lasts from 10 to 30 minutes, depending on the number of follicles to puncture and the technical difficulty. The liquid is delivered directly to the embryologist to locate the egg using a microscope and then place it on a specific culture medium in a cell culture dish. There might be follicles that do not contain eggs. In rare cases, it is possible that no ova can be produced although ovaries have been stimulated with the adequate medication.
The eggs are then placed in special incubators at appropriate temperature, humidity and ventilation conditions. After ovulation, the woman stays in the “recovery”room for 1-2 hours before going home. She usually does not feel pain, but it may be necessary to administer a simple painkiller, e.g. paracetamol (Depon – Panadol).
Egg retrieval is a very safe procedure, but as all surgeries must be performed in places that have organized surgery and infrastructure, such as hospitals, in order to deal with rare complications such as anaesthesia complications, bleeding, bladder injury etc
Dr. Ioannidis assures you that at the MITERA IVF unit the safety of the woman is above all and recommends that you avoid performing any surgical operation in places that do not provide hospital safety and infrastructure.
On the day of egg retrieval sampling the man must give a sample of sperm. The semen is taken by masturbation in a sterile urine collection in the special “private” spaces of the MITERA maternity hospital IVF unit. For better sperm quality, we recommend to the man to abstain from ejaculation 3-5 days before oocyte. The sperm sample is processed in the laboratory before being placed together with the ova for fertilization. This process activates sperm cells and enables them to fertilize the ova.
Quite often, sperm is a cause of anxiety for men, which can cause erection and ejaculation, reduced volume or significant delay. In order to avoid such a situation, the man should have informed us that we have prepared him psychologically, or have him freeze the semen a few days before, so as to get rid of the urgent stress or give him a mild sedative. If the sample has to be transported from home to the laboratory it should be done within ½-1 hour and the transfer is done at body temperature. In cases of azoospermia (no sperm during ejaculation), spermatozoa is obtained directly from the testis by biopsy.
Conventional IVF fertilization
Some hours after egg retrieval, ova and sperm are brought into contact via the appropriate sperm processing by biologists. This can be done in two ways.
When the sperm sample is of “good quality”, i.e. it has normal values in its parameters (volume, number of sperm, mobility, forms) we apply conventional IVF, where the eggs are placed in a high concentration of sperm and incubated under the appropriate conditions. One of these sperm will fertilize the egg by penetrating its outer membrane. The ova are then placed on special dishes (disks) in ovens.
When the sperm sample is not of “good quality”, ICSI microfertlization is performed [link], i.e. placing a sperm in the egg with the help of a micropipette.
The next morning, about 16-18 hours after contact with the ovum and sperm, fertilization is controlled. The existence of two pronuclei (small round formations) in the center of the ovum indicate the achievement of normal fertilization. The fertilization rate in the laboratory ranges from 60% to 100%. The state of the eggs (degree of maturity, cytoplasm nature), sperm fertilization ability and management and culture in the embryological laboratory are some of the factors responsible for the variation of the above percentage. There are couples with very low fertilization rates or no fertilization. If the fertilized eggs are few in number, but the embryos being developed are of good quality, then we have equally good rates of pregnancy.
Very rarely, complete fertilization failure can occur, so there are no embryos to be implanted. Fertilization failure may be due to egg quality, sperm quality or even difficulty in combining ova and sperm. In some cases, it is considered necessary to fertilization to be performed in a subsequent IVF cycle using ICSI microfertilization [link] or IMSI [link]. If this happens, you will meet Dr. Ioannidis and the embryologists for a direct analysis of the possible causes and in order to plan how to address this occurrence.
When the sperm sample is not of “good quality”, i.e. it has abnormal values in its parameters (tumor, sperm count, motility, forms), or when fertilization failure has preceded a prior conventional IVF cycle, then ICSI microfertilization is performed, i.e. placement of a spermatozoon in the egg with the use of a micropipette under microscopic monitoring.
The microfertilization technique is recommended when:
- there is moderate or severe oligo – astheno – teratospermia,
- there is a large percentage of sperm agglutination,
- failed attempts have been made with conventional IVF in which a low or no fertilization rate has been observed,
- the woman is older, so the eggs are few and covered with a harder shell membrane.
This technique has now provided a solution for couples with intense male infertility. The fertilization rate by micro-fertilization is 65-75%.