Factors Affecting Treatment Success In Assisted Reproduction Treatment

The use of the same-level assisted reproduction technology in Turkey as that of Europe and the US in Turkey raises treatment success rates of assisted reproduction treatment. Major advances in the assisted reproduction technology; including recent innovations in genetic testing, advances in embryo-related procedures, developments in egg and sperm freezing, the introduction of microfluidic chips, and serum treatment have been implemented in Turkey simultaneously with Europe and the US. All these developments aim to achieve the maximum chance of establishing pregnancy via the transfer of the best quality embryo at the most suitable time and under optimum conditions.

What affects the success of assisted reproduction treatment?

Age of the Candidate Mother

One of the critical factors affecting success in assisted reproduction treatment is maternal age. As maternal age advances, the success of assisted reproduction treatment shows a significantly declining trend. With progressing age, several problems start occurring such as

• *Aging of ovaries,
• Reduction in fertilization rates,
• Reduced ability of the internal lining of the uterus for the implantation of the fertilized egg,
• Endometriosis and increasing incidence of myomas
• Increasing need for surgery with potentially unfavorable effects.

Detection and removal of intrauterine abnormalities that may hinder the implantation of the embryo; including adhesions, myomas, or polyps, are important to prevent infertility in women. Therefore, to check whether the uterine cavity is normal, an ultrasonographic examination of the intrauterine cavity is performed via administering liquid agents into the uterus. The SIS technique can be used; which is a simple and painless method. Another method is uterine radiography (HSG); which is commonly employed to investigate such potential problems. However; because the HSG method can induce pain and may pose the risk of infection, such hysteroscopic examinations are preferred to be conducted in Eurofertil Assisted Reproduction Treatment Centers. Hysteroscopy is an easy method that allows for the examination of the uterine cavity in detail by means of a small camera system placed inside the uterus. Also, it allows for the correction of intrauterine abnormalities. Hysteroscopy is employed to identify intrauterine factors in cases with recurrent failures in assisted reproduction treatment.

Fluid collection in tubes is one of the most important and common reasons that reduce the success chance of assisted reproduction treatment in women. Detection of patient-specific factors and selecting the optimum treatment option specifically for each patient, namely carrying out a personalized treatment approach, are among the major factors affecting success in assisted reproduction treatment.

In Eurofertil Assisted Reproduction Treatment Centers and in Turkey; under the leadership of Dr. Hakan Özörnek, almost "golden eggs" are obtained from candidate mothers  via the "golden egg" method. The egg reserve of a woman has already been determined at birth and it is by no means possible to change it. The egg is at the same age as the woman is. So, as women age, their eggs age, too. Sometimes; regardless of age, ovarian aging can be observed even in very young women. Aging eggs cause significantly reductions in the chance of becoming pregnant. While it is possible to retrieve 8-10 eggs from 20-30-year-old candidate mothers during assisted reproduction treatment, the number of eggs that can be collected from 40-year-old candidate mothers decrease to 1-2.

Body Weight

Studies so far have demonstrated that excess body weight unfavorably affects fertility. Adopting a healthy diet and maintaining the optimum body weight are important factors to protect fertility in women. Also, being too slim is another unfavorable condition for candidate mothers. Just as excess body weight, being underweight too can become a hurdle on the way of becoming a mother.

Smoking

Smoking is something that should be avoided anyhow to maintain a healthy life. However, avoiding smoking is much more important for candidate mothers as it not only prevents the establishment of pregnancy but poses risks to the pregnancy process and the fetal health.

Stress

One of the major problems of today is stress. Stress inflicted by either social life or working conditions affects the process of becoming pregnant in candidate mothers unfavorably. Also, the inability to become pregnant despite efforts stands alone as an individual stress factor. Therefore, candidate mothers should exercise care to control their stress and they should ask for professional assistance when necessary.

Infections

Vaginal infections can be caused by fungi, bacteria, or some parasites. Vagina infections can be transmitted from woman to man and may act on sperm viability and motility in men, leading to infertility. Candidate mothers should immediately consult a specialist and start treatment in case they have such problems.

Hormonal Disorders

• Prolactin, the milk-producing hormone, is secreted by the pituitary gland. Thyroid gland diseases and elevated levels of the prolactin hormone can be causes of infertility. However, these conditions can be diagnosed by testing hormone levels in the blood and they are treatable.
• Polycystic ovarian disease and the resulting potential increase in insulin hormone can cause infertility or miscarriage.
• Congenital disorders, disorders of the immune system, or coagulation disorders can cause infertility, too. Detection and treatment of such factors affect treatment success in assisted reproduction treatment.

The Egg Reserve

Not the aging of the uterus but of eggs create hurdles on the way of the establishment of pregnancy. The frozen eggs retrieved from a 30-year-old woman will remain at the age of 30 even when the woman turns 40. The aging of the uterus does not prevent the fertilization process but eggs must remain young to achieve fertilization. Therefore, "egg reserves" can be considered the most important treasure of a woman. Today; married women, who intend to postpone their fertility, need to seriously consider undergoing assisted reproduction procedures and freezing their fertilized eggs (embryos), especially if they are older than 35 years old.

What is egg freezing?

Egg freezing is the process of storing the egg (oocyte) obtained from the ovaries of the woman for future use. With this method, the eggs are retrieved from the ovaries under vaginal ultrasonography and frozen in vitro by the vitrification method. The egg freezing method allows for the preservation and storage of the eggs for 5 years (as required by law). If the person wishes to extend this period at the end of 5 years, this period can be extended by obtaining permission from the Ministry of Health.

Who can have their eggs frozen?

Although the Ministry of Health previously allowed for egg freezing only for patients undergoing cancer treatment; with the new regulation coming into force, all women with low egg reserves have been offered “the right to freeze their eggs”, in other words, they have been offered “the chance of becoming a mother”. Young women with low egg reserves, either married or single women, can have their eggs frozen and choose to become a mother when they wish. As per regulations issued by the Ministry of Health, frozen eggs can be stored for five years. If the person wishes to extend this period at the end of 5 years, this period can be extended by obtaining permission from the Ministry of Health.

Sperm Factor

The quality, number, morphological health, and mobility of sperms in men are the determinants of the establishment of pregnancy. Detected abnormalities in a spermiogram plays a determining role on the success of assisted reproduction treatment.

Genetic Diagnosis Test: PGT

In assisted reproduction treatment, collecting cells from the embryo via interventional methods and carrying out diagnostic and screening procedures on those cells to detect genetic diseases or abnormal chromosome numbers are very important in order to ensure a healthy pregnancy period and the delivery of a healthy baby. Genetic testing is of vital importance, especially when the maternal age is advanced. These pre-pregnancy screening procedures are called pre-implantation genetic diagnosis/screening (PGT). In the PGT method, we aim to select the embryo with the normal chromosome number and to place that embryo into the candidate mother's uterus after obtaining the embryo formed by the fertilization of the egg cell from the woman by the sperm of the man via the microinjection method (ICSI). Thus, we aim to reduce the risk of miscarriages and eliminate the risk of a need to medically terminate the pregnancy because of abnormalities in the number of chromosomes.

Firstly, the embryo of the couple must be obtained after the couple decides to have a PGT for chromosomal examination. On the 5th day of the embryonal development, a few cells are taken from the embryo via a biopsy procedure to be carried out by an embryologist. Then, the cells are examined through the "Quantitative PCR" (q-PCR) method.In this procedure, only numerical analysis of chromosomes can be made and as a result of the analysis, the number of chromosomes in the cell's content is determined. The geneticist identifies cells as normal or abnormal as a result of the numerical evaluation of chromosomes. When the examined cell is determined to be normal, other cells that make up the embryo are also expected to be normal.

Families with identified genetic disorders in their close family members or in their relatives or families with a child diagnosed with a defined genetic disease should be very careful. We would like to make a call to these families; “–This test examines all chromosomes (23 pairs) in the cell only numerically. Balanced or unbalanced chromosomal disorders, single gene diseases and other genetic disorders are not included in the range of detectable disorders via this method. If you know a child or children with a genetic disease in your family or among your close relatives, you should definitely report this to your doctor! In such cases, you will be recommended to undergo further genetic diagnostic tests specific to the identified genetic disease.” In the later months of pregnancy, prenatal genetic diagnosis in addition to the tests above can be recommended by your physician if deemed necessary based on the ultrasound findings. These prenatal tests can be carried on by using the cells of a chorionic villus sample (CVS) in the first trimester or by using the amniotic fluid in the second trimester.

The new genetic test allows for the screening to be performed on the 5th day of the embryo.  Previously, we could obtain the results of the screening test performed on the 5th day of the embryo after 12 hours. In those cases; even when favorable results were obtained, the embryo was frozen and stored to be transferred the next month because the optimum period for the transfer of the embryo was missed.

It is possible to obtain results after 4 hours through the new genetic screening test. Thus, we can transfer the embryo on the same day without the need for freezing.
On the other hand; this genetic screening test is much more inexpensive than previous tests, offering an important advantage for families.

A detailed sperm analysis in men is critical. Genetic tests including the Y-chromosome microdeletion test and sperm FISH test should be performed if a significantly low sperm count or motility loss and deformities of sperms are detected. If problems are detected in these tests, preimplantation genetic diagnosis techniques should be used in starting a new cycle of assisted reproduction treatment. In addition, recurrent failures in assisted reproduction treatment cycles is one of the frequently encountered problems in couples with severe male infertility problems. The poor quality sperm used in such approaches unfavorably affect the embryonal development and reduce the chance of attachment of the embryo to the uterus. In such cases, it is very important to examine sperms in detail and to identify the existing severe deformities before treatment. For the last couple of years, we have been using special high-magnification microscope systems developed for this purpose. In this method called IMSI, we examine the sperms under 6000 times power instead of 200 times, using high-power magnification lenses and special optical systems. Thus, we can identify abnormalities in the sperm's head containing in the sperm nucleus with the genetic structure. Abnormalities in this region result in reduced success rates via causing  some problems including fertilization failures and slowed or stopped embryonal development. The IMSI system allows for the selection of sperms free of these disorders, increasing the chance of establishing pregnancy. However, the use of the technique requires trained biologists and expensive special systems, as well as longer procedures.

Blastocyst Transfer

Another method that we use in recurrent unsuccessful assisted reproduction treatment cases is to grow the embryos until the fifth and sixth days of development so that we can identify and select those embryos with a higher chance of implantation. Embryos that can achieve this developmental stage are called blastocyst and these embryos have higher implantation ability. Also, we can prevent the establishment of multiple pregnancies because fewer embryos will be transferred at this stage of development. Through the transfer of only 1 or 2 embryos, not only a higher chance of achieving pregnancy can be accomplished but also the risk of triplet pregnancies can be ruled out. Another advantage is that slowly growing and poor-quality embryos will be detectable by the 5th day of the embryonal development and, therefore, such embryos are eliminated automatically. In other words, some of the embryos that appear well on the second and third days of development cannot make the 5th to 6th days. When some well-looking embryos are selected and transferred to the patient early in their development (on the 2nd or 3rd day), they can be eliminated spontaneously at the blastocyst stage. Therefore, blastocyst transfer is another option for couples experiencing failures through treatment cycles.

What are the other optional methods that can be used to grow better quality embryos?

In couples with normal results obtained in all of the abovementioned tests but failures in assisted reproduction treatment cycles, we take tissue samples from the uterus and cultivate and reproduce this sample in a laboratory environment. Then, we develop embryos in this culture environment. In this technique called endometrial co-culture, a small tissue sample taken from the uterus on the 21st day of the menstrual cycle is reproduced under laboratory conditions to mimic the intrauterine tissue. Then, obtained embryos are placed in this tissue and left for growing. The intrauterine tissue culture; rich in growth factors, proteins, and nutrients necessary for embryo development allow for the development of the embryo. Furthermore; the antioxidants occurring in the environment removes waste material that may be harmful to the embryo. This technique is used as an alternative to artificial culture media in patients with previous failures in assisted reproduction treatment cycles.