In Vitro Fertilization (IVF) = Fertilization in the test tube (Artificial insemination)

"In Vitro Fertilization" can help those couples whose desire for children is not fulfilled naturally to finally hold their longed-for baby in their arms. There is a variety of different methods of In Vitro-Fertilization (IVF).

1. Insemination
2. In Vitro Fertilization - IVF
3. Choice of blastocysts
4. ICSI
5. IMSI
6. Special techniques
7. Cryopreservation- Freezing


The essentials of Assisted Reproductive Medicine are to achieve MAXIMUM success of each individual situation.

This can only be done by optimizing all areas in order to get the most out of it, starting with optimally preparing the treatment, establishing the ideal treatment-stimulation-plan, applying the best oocyte / follicle-puncture techniques to excellent laboratory work including the choice of blastocysts and IMSI and last but not least a well-performed embryo transfer implying an optimized aftercare medication plan after embryo transfer/insemination and throughout pregnancy.

 

 

Correlation between age and the chances of getting pregnant

The chances of achieving pregnancy resp. the “Baby – Take – Home- Rate” (BTHR – birth of a child) decline naturally with age (mainly the woman’s age):


 
Pregnancy Rate and Baby - Take - Home - Rate related to the woman's age

In IVF a variety of factors may arise, that can have an additional negative impact on the outcome of the age group involved:

• Hormonal imbalance not being appropriately treated with medication
• Endometriosis
• Uterine - malformations
• Benign uterine tissue growth (uterine leiomyomata)
• and many more...

As a first step, IUI may be recommended to young women (up to 36 years of age) with the option of 3 to 6 cycles. Basic preconditions, however, are non-obstructed fallopian tubes in the woman and a normal semen analysis in the man (according to WHO criteria).

A Polycystic Ovary Syndrome (PCOS) often is the underlying cause when the desire for children remains unfulfilled. In this case, stimulating hormones (gonadotropins, chlomifene) are being used to induce the ripening of 1 - 2 follicles in the ovary.

Subsequently, ovulation will be triggered by injecting human chorionic gonadotropin (hCG) and the semen is placed into the uterine cavity.

Sperm cells migrate through the uterus into the fallopian tube where they meet the oocyte. Fertilization of the oocyte by only one single sperm typically occurs in the ampulla (upper part of the fallopian tube).

Then the fertilized egg (zygote) starts its 5 days migration towards the uterine cavity. At blastocyst stage it then reaches the uterus and starts implanting.

To appropriately prepare the inner lining (endometrium) of the uterus for implantation, certain hormones (e.g. progesterone) have to be taken either until the heart can be seen beating via ultrasound four weeks after ovulation or embryo transfer or up to the 12th week of pregnancy.

     

Due date calculator

Since 1978 in vitro fertilization and subsequent transfer of the embryo are available to treat infertile couples, even in case of tubal blockage, various conditions of hormonal imbalance or if male factors (lack of mobile sperm in the semen or poor sperm quality) account for infertility.

Basically, "In Vitro Fertilization" or "Extra-Corporal Fertilization" refers to the fusion of ovum and sperm outside a woman's body.

This is done by removing the oocyte from the ovary and subsequently joining it with the man’s sperm in a petri dish (= in vitro).

        

Fertilization: The sperm is injected directly into the oocyte using the ICSI procedure.

Two to five days later the subsequently obtained embryo will then be transferred to the uterine cavity (embryo-transfer).

Such a treatment represents a great challenge to the couple. That is why we aim to provide individual treatment in a caring atmosphere.

The couple has to be informed about all details and aspects of the various treatment options. After a review of all existing test results and a thorough gynecological examination and assessment of semen analysis, a therapy schedule will be issued. In some cases it proves to be favorable, if the couple undergoes psychological counseling prior to in vitro fertilization.

After a preliminary consultation each couple is given a leaflet and therapy plan with detailed description of each examination (ultrasound scans, hormonal assessments, blood tests etc.) as well as details on the medication.

To meet each couple’s individual needs, the treatment is tailored to the particular situation involved in every single case.

3.1. The rational behind opting for the best developing blastocysts after artificial fertilization
3.2. The high art of In-Vitro-Fertilization

After egg-retrieval (follicle puncture) and subsequent fecundation of the eggs by IVF, ICSI or IMSI, the embryos have to be transferred to a culture dish containing a nutrient medium. 

They are now left to themselves in an incubator. After 16 to 18 hours of incubation there is a first microscopic evaluation that will reveal how many of the eggs have been fertilized (usually more than 70% of obtained eggs).


        
Incubator and culture - dishes for embryos


Until 1996 embryos used to be placed into the uterus (embryo transfer) 2 – 3 days after follicle puncture with the embryo consisting of 4 – 8 cells. The development of new media now enables us to keep the embryos in culture for a longer period of time and subsequently transfer one or two of them on day 5 (rarely on day 6) at the blastocyst stage.

Today, at our IVF Centers embryo transfer is almost only performed at the blastocyst stage.

3.1. The rational behind opting for the best developing blastocysts after artificial fertilization

 

3.2. The high art of In-Vitro-Fertilization

 

.

 

Extra-corporal fertilization offers very good chances of successfully treating unwanted childlessness due to male infertility.

The procedure called Intra-Cytoplasmic Sperm Injection (ICSI-procedure) in 1992 became a milestone in fertility treatment and since then is widely accepted (report).

This technique allows the injection of a single sperm directly into the cytoplasm of an egg in order to fertilize it.

Video: Fertilization of an egg by a sperm using the ICSI procedure

Fertilization rates of more than 70% can be achieved by using the ICSI procedure. That also applies to patients having an extremely low sperm count.

If no motile spermatozoa are present in the ejaculate, this method may help overcome infertility in men. Due to conditions affecting the vas deferens there may be no sperm in the seminal fluid. In these cases it is possible to aspirate spermatozoa from the epididymis and use it for ICSI (PESA/MESA). If no sperm is detectable in the epididymis, sperm could be retrieved directly from the testes (TESE/TESA).

Pregnancy rates as achieved by ICSI equal those obtained by conventional In vitro fertilization.

Nevertheless, in our opinion the ICSI procedure is an obsolete technique now and therefore has been replaced by the IMSI procedure at our centers.

In conventional IVF (in vitro fertilization) the zona pellucida (strong membrane that forms around an oocyte) functions as biological barrier against abnormal sperm, so that in most cases only “normal” sperm is able to fertilize an oocyte.

In the previously described ICSI procedure this “natural” selection method is bypassed and instead the biologist decides on the best spermatozoa after morphological assessment (usually at a magnification of 200-400 x). (Literature)

The quality of the subjective assessment and subsequent selection can additionally be enhanced using a high resolution microscopy technique such as “Intra-cytoplasmic Morphologically Selected Sperm Injection” (IMSI).


Electron microscope image of sperm:  picture 2 and picture 3 show structural defects in sperm head.
Such defects can be displayed by the IMSI technique.

Studies performed by our team have shown that the likelihood to isolate a normal spermatozoon without or presenting only a small vacuole (= defect in sperm head) (≤ 4% of sperm head’s surface), has been notably increased through the use of IMSI compared to using the ICSI procedure.

Spermatozoa presenting large vacuoles (> 4% of sperm head’s surface) can have a negative impact on embryonic development potential. Only from the third day of embryonic development the genome in the sperm cell is switched on (late paternal effect). See explanation already set out in point 3.1.

6.1. In Vitro Maturation
6.2. Spindle - View
6.3. Pre-Implantation - Diagnostics
6.4. Polar Body - Biopsy
6.5. Blastomere Biopsy (performed on day 3 embryos)
6.6. Trophectoderm - Biopsy on blastocysts
6.7. Assisted Hatching - (helping the embryos to "hatch")
6.8. PICSI
6.9. PolScope

6.1. In Vitro Maturation

In some special cases or if conventional stimulation for IVF / ICSI /IMSI is contra-indicated in a woman, In Vitro Maturation (IVM) may present another therapeutic option. The method involves collecting oocytes from immature follicles that are subsequently left to mature in a culture medium.

So far, success has been limited and scientific research has not yet been concluded. At our centers we perform this technique at the most advanced state of the art international standards. After appropriate consultation, we offer In Vitro Maturation to the following patients:

• Patients who are at high risk of Ovarian Hyperstimulation Syndrome or suffer from Polycystic Ovary Syndrome (PCOS). New ovarian stimulation techniques and specific therapeutic measures, however, reduce the risk and thus an IVM will seldom be required.

• Patients prior to chemotherapy when it is too late for ovarian stimulation and this procedure would only lead to further complications.

The disadvantages of an IVM are as follows:

• Overall, only few egg cells mature in the petri dish. Furthermore, there might be negative effects on the growth processes of embryos and fetuses having developed from such eggs.

• The examination of human embryos revealed that 80% of all embryos resulting from IVM presented chromosomal disorders.
  
  
  

6.2. Spindle View

The spindle is an essential organelle of the egg and plays a central role in meiotic development of human eggs . The spindle is responsible for accurate alignment and distribution of the chromosomes during cell division.

In 15-20% of all cases the mature egg lacks the spindle before being fertilized by a sperm. The presence of the spindle is – in addition to the first polar body – an indicator for maturation of the egg cell.
Increasing female age is associated with more spindle disorders. The absence of the spindle correlates with considerably reduced fertilization rates and poor or even no embryonic development.

 

The position of the spindle during ICSI / IMSI affects further embryonic development, too. Usually, the egg is positioned in such a way that the first polar body is at 12 o`clock and the injection of the sperm cell is performed at the 3 o` clock position. If the spindle isn’t optimally aligned (the spindle is normally close to the first polar body and thus quite in a distance from the site where the sperm is injected into the cytoplasm) it might be accidentally damaged when using a glass pipette for sperm injection, thus leading to the destruction of the egg .

Even in cases of repeatedly failed fertilization, spindle view represents an option (where appropriate, subject to be discussed with a doctor).

Picture: Display of spindle with the chromosomes within a mature egg and in the polar body, respectively

6.3. Pre - Implantation - Diagnostics

The Pre-Implantation-Diagnostics (PID) or Pre-Genetic-Diagnosis (PGD) as it is known in Anglo-American countries has originally been developed as an alternative to Prenatal-Diagnosis. Prenatal diagnosis is only possible when a pregnancy is already established, whereas PID can be performed on the embryo before pregnancy occurs.

The PGD is performed by examining a single cell with regard to aneuploidy (mal-distribution of chromosomes) and genetic diseases (overview, genetic diseases in detail, example: retinoblastoma). This can either be done by using the Polymerase Chain Reaction (PCR) or the Fluorescence In Situ Hybridization (FISH) method.

The PID can also be used to do an HLA-Typing on the embryo. This method can be performed, if there is a medical indication, for example a sibling suffering from a severe disease can benefit from cord blood stem cells of a baby-brother/sister (e.g. Fanconi-Anemia, Leukemia, Auto-Immune diseases…).

If, due to a malignant disease, a child’s bone marrow has to be destroyed by chemotherapy or radiotherapy, the sick child’s only survival chance would be to have a bone marrow donation either from a sibling or another suitable donor or to receive stem cells from a cord blood donor to rebuild the hematopoietic system. HLA typing can be used to have a child that apart from fulfilling the desire for another baby can donate hematopoietic stem cells to save its sick sibling.

6.4. Polar Body - Biopsy

Polar body diagnostics allows conclusions to be drawn regarding the genetic material of the maternal egg-cell. Hence, the mal-distribution of chromosomes and the genetic predisposition towards certain diseases can be confirmed or ruled out with a high degree of probability.

This technique enables us to reduce the risk of miscarriage, especially if it is related to advanced maternal age, whereas it may lead to a slight increase in pregnancy rates. We are pleased to provide you with further details on this technique during a personal consultation.

6.5. Blastomere - Biopsy (performed on day 3 embryos)

The biopsy is performed by removing a single cell or a maximum of two cells (blastomere) from the embryo, usually on the 3rd day after fertilization at the 6-8 cell stage.

This diagnostics is notably used in case of a known genetic disorder within the family. Thus, it is possible to specifically diagnose, if the embryo is also a carrier of the genetic disorder. Only those embryos that are free of genetic abnormalities may then be used for embryo-transfer.

In certain cases, this diagnostics may be suitable for investigating chromosomal disorders (aneuploidies) (e.g. chromosomal translocations).

To date, Polar Body Diagnosis still is the “Gold Standard” in aneuploidy-screening. We were able to show this together with the late Yury Verlinsky who pioneered the PID.

Reference 1
Reference 2

We offer the PID/PGD to be performed on blastomeres at our IVF-Center in Pilsen in the Czech Republic.

6.6. Trophectoderm biopsy on blastocysts

The analysis of cells that had been removed from the blastocyst on day 5 of embryonic development (trophectoderm biopsy) is a technique that we are still in the process of further developing together with Alan Handyside (pioneer in PGD). This technique isn’t routinely offered at our centers yet.

In the future we hope that due to this technique, however, chromosomal disorders (aneuploidy) as well as genetic diseases (overview, genetic diseases in detail) can be detected by using a single diagnostic (whereas to date, it is necessary to combine the methods of polar body diagnostics and blastomere biopsy on day 3 embryos).

Analyzing blastocysts requires optimum freezing methods, since this procedure mostly exceeds the time the embryos can be kept in culture. We are proud to count among our longtime staff members, Dr. Pierre Vanderzwalmen, who is a pioneer in the field of freezing.

References

6.7. Assisted Hatching - Helping the embryo to "hatch"

This method aims to make it easier for the developing embryo to hatch from the zona pellucida. The assisted hatching procedure involves thinning or making a small hole in the zona pellucida. This can be performed mechanically, chemically or by using a laser-beam.

Performing this procedure is mainly useful in women with embryos having a very thick and tough zona pellucida (can easily be recognized using a polscope or an ordinary light microscope). In particular with increasing age, the zona pellucida in some women becomes thicker and toughened. The same negative effects on the zona pellucida have been found in embryos after freezing and thawing.


    
Hatching embryo on day 5                            Hatching embryo on day 6

Depending on the specific medical findings this technique is not routinely applied in our IVF laboratories, but according to individual requirements.

6.8. PICSI

PICSI is a method to select mature sperm to be used for ICSI (ICSI, IMSI). The heads of mature spermatozoa have a specific receptor for hyaluronic acid (hyaluronan). Hyaluronan is a major component of the protective layer that surrounds the oocytel. Immature sperm cells do not have such a receptor.

The hyaluronic acid binding test (PICSI) hyaluronan is used to select between immature and mature sperm cells. It has shown that mature sperm bind to hyaluronan where they can be isolated and used for ICSI / IMSI.


    
Washed sperm in a petri-dish                                       Collecting the bound sperm

This technique is used in specific cases only. PICSI cannot replace the IMSI technique, but is capable to complement it in certain cases.

6.9. PolScope

The zona pellucida (Zona pellucida,) is a glycoprotein membrane consisting of 3 layers surrounding an oocyte or embryo until the embryo performs zona-hatching on day 5 – 6 of embryogenesis at the blastocyst stage.

Using a polscope the zona pellucida can be assessed regarding the thickness of all three layers. Such data allow a better determination of quality properties of the zona pellucida of oocytes and embryos.

The inner layer of the zona pellucida in particular seems to be an important non-invasive marker for the development potential of an oocyte. There is evidence that in patients above 35 years of age the inner layer of the zona pellucida is thicker and the zona pellucida’s glycoproteins seem to be less structured.

 
Freezing and storage of biological material is performed at low temperatures. These temperatures can be achieved by using liquid nitrogen (-196°). Under these conditions, the cells can be stored over a long period without impairment of their viability and function.

Specific cryopreservation techniques that are exactly tailored to the cell-material to be frozen enable us to cryopreserve the following tissue material at our IVF Centers.

    

7.1. Cryopreservation of sperm and testicular tissue
7.2. Cryopreservation of unfertilized oocytes
7.3. Cryopreservation of fertilized eggs (zygotes)
7.4. Cryopreservation of embryos
7.5. Cryopreservation of ovarian tissue / tissue from the ovary

7.1. Cryopreservation of sperm and testicular tissue

Sperm can be extracted from the ejaculate, from the epididymis or from the testes. All these sperm cells can be frozen and thus cryopreserved for further treatment.

For tumor patients it makes sense to have their sperm cryopreserved prior to undergoing chemotherapy or radiation, thus being able to fall back on this stored material in case of a later infertility treatment.

Investigations have shown that storage times of up to 30 years do not impair the sperm quality. (In theory, the storage periods could be much longer, however, in this area appropriate expertise is still lacking).

Donor sperm can be frozen, too. Six months after cryopreservation of the sperm, the donor is reinvestigated for the presence of specific infectious diseases in accordance with legal requirements. Only if the results of the tests are negative the semen sample is released after this quarantine period of six months.

Further information on cryopreservation of sperm

7.2. Cryopreservation of unfertilized oocytes

Owing to social circumstances, more women are planning to have their first baby later in life, i.e. after having completed their professional training and once their financial situation has been stabilized etc. Most women do not reach this desired situation before age 35 or older.

For this reason and due to the negative "aging-effects" on the number and quality of oocytes it is getting more and more difficult to achieve pregnancy after the age of 38. Therefore, we recommend you to have your oocytes cryopreserved at an early age (between 20 and 35 years of age) as a precaution.



    Metaphase II - oocyte

Thus, you will have optimum chances to conceive a baby despite age related decline in female fertility. (You may wish to get pregnant e.g. between 40 and 45 years of age).

At our centers we offer this cryopreservation procedure at the highest possible technical and quality level.

More information on the freezing of unfertilized oocytes / oocyte – preservation

7.3. Cryopreservation of fertilized eggs

Technically, freezing pronuclear-stage zygotes (zygote)
on day 1 of development is an uncomplicated procedure.


The development rate of frozen thawed pronuclear zygotes
to the blastocyst stage is very high (95%).

7.4. Cryopreservation of embryos

Embryos can be frozen at any stage (from day 2 to day 6) of embryonic development. The conventional procedure of slow freezing as well as the vitrification procedure (ultra-rapid freezing in liquid nitrogen) is being successfully performed at our IVF Centers (the development rate of frozen and thawed embryos is high (90%)).

Due to these cryopreservation procedures surplus embryos resulting from an IVF treatment can be preserved for a future pregnancy.

Slow freezing / slow thawing (ice-crystal formation controlled by seeding).

Vitrification/glass-like state (solutions are converted into a glass-like solid state, free of any crystalline structures).

7.5. Cryopreservation of ovarian tissue / tissue from the ovary

If the impairment of ovary function is to be feared for patients suffering from malign illnesses, which may severely complicate or even prevent the occurrence of pregnancy, in addition to oocyte cryopreservation, ovarian tissue may be frozen.

Women who may just not yet have found the right partner or women for whom it is not yet possible to have a child because of job-related reasons can have their oocytes or ovarian tissue frozen at an age of 25-35 years to cryopreserve them for future use in fertility treatment.