- Stimulation of the ovaries
- Ovum pick up (OPU)
- Egg fertilization and observation of its development
- Embryotransfer (ET)
- Embryo culture
- Intracytoplasmatic injection (ICSI)
- Assisted hatching (AH)
- Embryo cryoconservation (CC) and its insertion into the uterine cavity (CET)
- IVF alternatives – native, minimal stimulation
- Success rate
- Treatment risks
Medications used for hormonal stimulation of the ovaries must be approved by the patient’s specific health insurance provider. There are two types: medications made from a female’s urine in climacterium (inexpensive and fully covered by health insurance) or synthetically manufactured hormonal substances that are only partially covered by insurance. Additional payments for synthetic hormonal medications vary between 3,000 – 5,000 Czech crowns for each IVF cycle.
If the ovarian response is low and requires more than 2,250 IU (international units) of the active substance in the medication, the patient is financially responsible to pay for the treatment without help from health insurance.
The long protocol is the most reliable and most commonly used method, and it shows the best success rate. The more recent and much simpler protocol uses GnRh antagonists. It is usually used for women with high risk of developing OHSS. The short protocol is appropriate for women with a low ovarian response to stimulation. Therefore, it is frequently used for older women.
Ovum pick-up (OPU)
Ovum pick-up is a very minimally invasive surgical procedure, during which the liquid containing the ova is extracted from the follicles in the ovaries. OPU is an outpatient procedure administered under anesthesia. A needle connected to the extracting device is inserted directly into the ovary through the back of the vaginal vault. The procedure lasts only a few minutes depending on the number of ovarian follicles (small cavities in the ovaries containing eggs). The number of ovarian follicles and the gathered eggs are determined by the individual’s ovarian tissue reaction. Eggs are then placed into the cultivation system in the embryologic lab, which ensures optimal environment for further development.
The patient is discharged two hours after bed rest. The side effects of the procedure include a very light bleeding and mild pain in the lower abdomen. On the evening of the day of the OPU procedure, the patient begins taking prescribed medication, which prepares the endometrium for egg nestling (progesterone – UTROGESTAN). They can be inserted vaginally or swallowed at a regular dosage of 1 – 1 – 2.
Actual outside the body (in-vitro) fertilization is performed in the embryologic lab (“in a test tube”) under very strict and highly controlled conditions. The ova are placed into a special solution providing nutrition and suitable living environment. The partner´s sperm cells are then added to the ova in the solution. Fertilization happens spontaneously – the sperm cells move independently by lashing, reach the egg and penetrate its outer layer. Cultivation of the ova and sperm cells together takes 16 to 20 hours. Then, the embryologist examines the solution and determines whether the fertilization was successful, with success characterized by the presence of the two pronuclei in the cytoplasm.
Intracytoplasmic Sperm Injection (ICSI)
If the partner´s sperm cells show a lower ability to successfully fertilize an ovum using standard IVF methods, it is possible to perform a specific micromanaging method: Intracytoplasmic sperm injection. Using this method, every ovum is directly injected with the most suitable sperm cell (with the best motility and other qualities).
ICSI is mainly recommended for the following: treatment of male causes of infertility (lowered sperm cell count, lower sperm cell motility, etc.), scenarios in which the sperm cells are surgically gathered, immunologic causes of infertility, in cases in which the standard IVF procedure fails, after repeated failures of assisted reproduction treatments, patients of older age, in cases when the cryo-conserved sperm is used, in cases in which donor’s sperm or ova are used and in some other cases. This method demonstrates a very high success rate. Although, it involves active interference with natural selection principles, no increased genetic risks have been seen.
The IMSI method is also very useful. It is basically a modified version of the ICSI. Sperm cells are chosen for their morphologic qualities – they need to be examined by a high resolution microscope.
Preselected Sperm Intracytoplasmatic Injection (PICSI) PICSI method allows for choosing mature sperm cells to fertilize the ovum. This method is based on a principle of mature sperm cell bonding with hyaluronan, which is an important natural component of the ovum´s outer layer. A mature sperm cell then quickly and successfully binds to the hyaluronan present in the egg’s cell membrane. In laboratory conditions, the mature sperm cell is bound to the hyaluronan by using special gel. It is later isolated to be used in the ICSI method. The PICSI method eliminates the use of immature sperm cells and lowers the following risks: embryonic developmental defects, implantation defects and frequent miscarriages. This method is selected if the ratio of the fertilized oocytes is too low, the embryos are not developing properly or in cases involving frequent miscarriages.
The above mentioned procedures are not covered by health insurance.
Embryo transfer to the uterus is usually performed two or three days after the removal of the ovum. If the fertilization was successful in more than five ova, it is possible to perform an extended cultivation, which extends the duration of the ovum cultivation in the embryologic laboratory for at least another 24 hours. The time the embryo reaches the blastocyst developmental stage (5 to 6 days) presents the most desired duration of extended cultivation. This method allows the physician to easily determine which embryos are developing well, exclude the embryos with defects and select the embryos with the greatest potential for successful implantation. One advantage of this method is a higher percentage of successful transfers because of embryo selection. This procedure is not covered by health insurance.
The transfer of embryos into the uterus is usually performed 2-3 days after the removal of the ovum or no later than 6 days based on the length of the cultivation. Embryotransfer is a pain-free procedure in which the embryos are inserted through the cervix into the uterine cavity using a thin device called a catheter. Two embryos are usually inserted but, in some cases, three can be transferred – if the woman is older than 35 or if previous IVF procedures repeatedly failed. In some cases, only one embryo is inserted. Transfer of a large number of embryos increases the risk of a multiple pregnancy.
The embryo´s potential for successful implantation can be increased by assisted hatching (AH). The embryo leaves a protective layer (zona pellucida) before it implants itself in the endometrium. Zona pellucida protects the ovum from a multiple sperm cell penetration, and hence a multiple pregnancy. If the zona pellucida is too dense or thick, the embryo can encounter problems dislodging. This usually leads to failed implantation. Assisted hatching increases the chances of successful conception for women over 35, in cases with a very strong zona pellucida, and in cases involving repeated implantation problems. Assisted hatching is a micro-manipulative procedure done by an embryologist. AH is performed by creating an aperture in the zona pellucida by laser or needle, which enables easier dislodging of the embryo before embryotransfer.
The patient is usually discharged after an hour of bed rest and is educated about certain precautions for the next few days.
The initiation of pregnancy can be confirmed by a pregnancy test 14 days after embryotransfer. During this time, the pregnancy is known as biochemical gravidity. After two or three more weeks, ultrasound is performed to examine the progress of pregnancy, the viability of the fetus and a possible multiple pregnancy. If a normal healthy pregnancy is confirmed, the woman is sent to her general gynecologist.
Embryo Cryoconservation (CC) and Insertion of the Cryopreserved Embryo into the Uterine Cavity (Cryoembryotransfer, CET)
After obtaining more than 3 high quality embryos, the unused embryos can be cryoconserved (frozen) and preserved for the next possible application. Frozen embryos are stored in a liquid nitrogen in very low temperatures (-196°C). When thawed, about 75% of all preserved embryos are ready to be used for the next cultivation or transfer. Approximately 25% can be damaged by the freezing process or they stop developing. Embryo insertion is done similarly to the standard IVF – cryoembryotransfer (CET).
IVF Alternatives – Native – natural IVF cycle
No hormonal stimulation of the ovaries is used in the natural cycle. The main goal is to obtain the only ovum that matures in the ovary during the female´s physiological menstrual cycle. This method shows low success rates mainly due to the fact that only one ovum is fertilized, but it is an inexpensive and safe method.
The goal of minimal stimulation is to obtain 2-8 mature ova. This stimulation approach is very gentle on the woman´s organism. Clomifene citrate pills (CLOSTILBEGYT) or injectable medication in very small doses is applied. Gathered ova are fertilized mostly by the ICSI method. Created embryos are then transferred into the uterus after 2 to 3 days of cultivation. This method is slightly less successful than the standard method which includes more hormonal stimulation, but it is safer and with lower OHSS risk.
The minimal stimulation method is intended for the following:
- couples with previous unsuccessful standard IVF treatments
- couples that did not succeed with a long protocol stimulation
- women with PCOS syndrome
- women with stimulation process affected by OHSS
- women who do not want stimulation with high hormonal doses
- couples who are able to cover expenses for a standard IVF treatment
Success Rates of IVF and CET Methods
Average worldwide success of the IVF method varies between 25% and 35% of clinical pregnancies following one cryoembryotransfer. The CET method shows approximately 50% success of transfers performed with non-conserved embryos.
Ovarian hyperstimulation syndrome (OHSS)
Multiple pregnancy – Conventionally, two embryos are simultaneously inserted into the uterus. Three embryos are considered a complication in assisted reproduction; it is recommended to lower the number of the developing embryos – to perform fetoreduction during week 10 – 11 of the pregnancy. A multiple pregnancy (double, triple, even quadruple) is usually followed by a much more frequent occurrence of complications. When compared to a normal (non-multiple) pregnancy, there is also a higher risk of premature birth and a higher rate of perinatal death and disease. A multiple pregnancy occurs in about 30% of couples treated with assisted reproduction methods.
Ectopic pregnancy – Is a scenario in which the embryo leaves the uterine cavity and nests in the oviduct. The probability of this complication is 2% in assisted reproduction compared to 1% in normal reproduction. Intrauterine and ectopic pregnancies can very rarely occur at the same time – one embryo nested in the uterine cavity while the other one is in the oviduct. If they are both recognized in time, the normal intrauterine pregnancy can usually continue.
Bleeding after oocyte removal – Bleeding in the puncture area rarely demands any additional treatment. Intravaginal bleeding can usually be quite easily stopped by a small suture. Stronger bleeding in the abdominal cavity requires laparoscopic or even surgical treatment and involves opening of the abdominal cavity. Possible infections are prevented by the administration of antibiotics.