What happens during IVF treatment?
- Stimulation (medication)
- Oocyte retrieval (removal of the mature egg cells)
- Fertilisation (conception itself)
- Transfer (placing an embryo or embryos back in the womb)
During the first consultation, the patients have the opportunity to get to know the doctor. The couple or patient receives extensive information about how we work, the chance of success and timing etc. This is also an ideal time to ask questions yourself or express any concerns. After this, we might go on to establish a schedule and make practical arrangements, and patients might be given a tour and introduced to our staff at the IVF centre.
2. Stimulation (medication)
In a normal menstrual cycle, one egg matures each month. With IVF treatment, we ideally need more eggs to maximise the chance of success. Giving the woman hormonal medication means that several eggs may develop in the ovary at once. An individual stimulation plan is drawn up for each woman. The patient is taught to administer the hormonal medication herself by the nurse. In some cases, it can also be done by her general practitioner or a nurse. At specific times, an ultrasound and hormonal assessment of this stimulation will be carried out. Depending on the results, the stimulation plan may be adjusted.
3. Oocyte retrieval (removal of the mature egg cells)
Timing is crucial in this phase. When the follicles are mature, ovulation is hormonally triggered by administering a special hormonal preparation. Ovulation itself usually occurs 37 to 40 hours later, but once the eggs are mature enough, just before ovulation itself, we remove them from the body by means of a follicle puncture under a light anaesthetic. The follicular fluid containing the mature egg cells is aspirated. After a quality check under the microscope by the lab technician, the eggs are placed in a nutrient suspension in the lab for further maturation. Retrieving the eggs takes about 15 to 30 minutes.
At the same time as the oocyte retrieval, the man provides his sperm sample. A second sample may turn out to be necessary, so the man needs to be available all day that day.
In preparation for the oocyte retrieval, the patient and her partner need to arrive at the IVF centre with an empty stomach (!) one and a half hours in advance. The oocyte retrieval itself is done under a light general anaesthetic and painkillers if necessary, administered through the anaesthetic drip. In exceptional cases, a follicle puncture can also be done under local anaesthetic. After the oocyte retrieval, the patient remains the hospital for a short time for observation after the general anaesthetic, but she can usually leave the IVF centre three hours later.
4. Fertilisation (conception itself)
A few hours after the eggs have been removed from the body, they are brought together with the partner's sperm in the lab. By the next day it will already be clear whether fertilisation has occurred, and if so, how many embryos have been obtained. Patients are always informed of the results by telephone.
Direct fertilisation always occurs according to the same procedure. A minimum of two hours after oocyte retrieval, the lab technician or embryologist rinses the eggs in a special medium containing nutrients and places them in a Petri dish. In the meantime, the man's sperm sample is processed in such a way as to select the most motile sperm (sperm washing). Then the sperm and eggs are brought together in an incubator (that acts like a womb).
By regulating the temperature (approx. 37°C) and CO2 content, this device simulates conditions in the uterus. About 16 to 18 hours later, the eggs are moved to a Petri dish with fresh medium. The embryologist/lab technician can now observe the eggs and find out whether fertilisation has in fact taken place. If this is the case, the result is called a zygote.
If direct IVF fertilisation as described above turns out not to be possible, there are several possible alternative methods.
5. Transfer (placing an embryo or embryos back in the womb)
In the days following oocyte retrieval and fertilisation, the fertilised eggs continue to divide. Depending on a patient's age and the quality of the embryos, one or two embryos are transferred back to the womb (this is specified by law). Only patients aged at least 40 years old are allowed by law to have an unlimited number of embryos transferred.
The monitoring, evaluation and ultimate transfer of the embryos happens between the second and fifth day after oocyte retrieval, always in consultation between the patient, gynaecologist and lab.
A transfer is only considered after thorough evaluation of the embryos on the basis of three parameters:
- The number of cells (blastomeres) of which the embryo consists
- The evenness of these blastomeres
- The fragmentation of the blastomeres
The combination of these three parameters determines the actual quality of an embryo. In other words, we decide during evaluation of the embryos what will happen to them. There are three possibilities:
- Destruction of embryos that do not continue to divide or are of poor quality
- Freezing or cryopreservation
- Returning the embryos to the womb by embryo transfer. This procedure is painless and so does not require an anaesthetic
After embryo transfer we have to wait and see whether implantation occurs. In this phase, extra medication is given to calm the uterus and thus create optimal conditions for the implantation of the embryos.
Waiting for the result can be a very stressful period, and our team is always available to coach and support you. Fifteen days after oocyte retrieval, we know whether the woman is pregnant.