Treatment using in vitro fertilization (IVF), also commonly known as test tube fertilization, takes place in five successive steps: stimulation, ovum aspiration and sperm processing, fertilization and embryo culture, embryo transfer, after-care and embryo freezing.

Step 1: hormonal stimulation

Many different types of hormonal stimulation exist in IVF. In the long treatment programme, the natural operation of the ovary is stopped using the contraceptive pill and the command centre in the brain, which controls the female cycle, is suppressed by the daily use of hormonal medication via a nose spray or subcutaneous injection. In the short treatment programme, the natural operation of the ovaries is not suppressed in advance, but hormonal stimulation starts on the 2nd day of the menstrual cycle. The actual stimulation takes place using subcutaneous injections of stimulating hormones. An ultrasound and blood sample are conducted every two days starting on day 6 or 7 in order to see whether the eggs are growing as desired. This takes place in the fertility centre or at a local gynaecologist's surgery. The LUFC can provide a list of gynaecologists with whom the centre cooperates closely. Based on blood and ultrasound results, the subsequent course of the stimulation is planned. As soon as the ova have grown sufficiently, the ovulation signal can be given (hCG: Pregnyl® or Profasi®). Ovulation will now take place after 36-38 hours.

Step 2: ovum aspiration and sperm processing

Just before spontaneous ovulation, the doctor pierces the follicles one by one and aspirates the fluid containing the ovum. This takes place using a fine needle mounted on to the vaginal ultrasound probe, usually following local analgesic or sometimes under general anaesthetic. The embryologist examines the fluid under the microscope, looking for the ovum, which he transfers to a fresh culture medium together with the surrounding cells. The ova are then placed in an incubator (37 oC) in fresh culture medium for a few hours.

On the same day as the ovum aspiration, the man produces a sperm sample after abstaining from sexual relations for three to five days. The sample is prepared, including counting the number of sperm cells and their motility. The sperm cells are separated from the seminal fluid and placed in the same culture medium as that of the ova for a few hours.

Step 3: insemination and embryo culture

Insemination is the moment when the ova and the sperm cells are brought together. A small amount of the prepared sperm sample is added to the dish containing the ova, after which it is put back in the incubator. Between 12 and 20 hours after insemination, the "pronuclei" are visible (under the microscope) in the ovum if it has been fertilized. The fertilized ova are placed in a fresh culture medium and again placed in the incubator for approximately 24 hours. The couple is told of the fertilization result and appointments are made for transferring the embryo(s). This usually takes place on day 2 after fertilization. Most embryos are then at the two-cell or four-cell stage. However, they can also be transferred later: on day three or even on day five/six. The advantage of longer culturing is that a better choice of embryo can be made and this can lead in some patients, but not all, to a higher probability of pregnancy. The day of embryo transfer should ideally be individually determined by the LUFC, taking into account the age of the woman and the number and quality of the ova and embryos.

Step 4: embryo transfer

Transferring the embryos is not usually painful and can be compared to the technique used for insemination. Once the embryos have been chosen (number of cells, appearance), the embryos are aspirated into a catheter which is then inserted high into the uterus via the vagina and the cervix. This is where the embryos are deposited. This procedure takes only five to ten minutes. Afterwards, the woman stays in bed for another 30 to 60 minutes. Depending on the woman's age and medical condition, only one to two embryos are usually transferred. This is in order to prevent the risk of triplets or multiple pregnancies. Embryo transfer is systematically performed using ultrasound monitoring and the woman should preferably have a half-full to full bladder.

Step 5: after-care or "what happens after embryo transfer?"

Following the procedure, the woman may resume her normal activities. Vigorous sports or physical exertion are not recommended for the first few days. Warm hip baths or steam baths and hot saunas are also not recommended since they have a harmful effect on pregnancy. The day after the embryo transfer, progesterone treatment is started (Uterogestan®, vaginal tablets) in order to keep the endometrium in optimum condition during the second half of the cycle. Two weeks after embryo transfer, a pregnancy test can show whether the embryos have implanted. These two weeks are a very tense period for many couples, with high expectations alongside fear of (another) failure. If the result of the pregnancy test is positive, the progesterone treatment is continued and a week later another blood sample is taken. If these results are also good, an ultrasound is scheduled as well as a final appointment with the fertility specialist. These last blood samples and ultrasound can of course also be performed by the woman's own gynaecologist. If the pregnancy test is negative, the progesterone treatment is stopped and further policy discussions are held.

Step 6: freezing surplus embryos?

Since more ova are usually fertilized than are needed for transfer (in order to increase the chance of success), embryos are often left over. These surplus embryos can be frozen and stored for possible use during subsequent IVF procedures. In this case, the uncomfortable hormonal stimulation and ova pick-up are no longer necessary. The treatment procedure therefore becomes much simpler. Usually, gentle hormonal stimulation is chosen in order to prepare the uterus properly for embryo transfer. Nowadays, some people also advocate using surplus embryos that are no longer eligible for development into babies for scientific research purposes. Opinions vary on this point depending on the fertility centre. Of course, the parents also have the right to decide, as is explained in the agreement they sign in this respect before beginning IVF or ICSI.