Failed IVF Trials
Failure to achieve pregnancy despite transferring good quality embryos in at least 3 IVF treatment attempts or failure to achieve pregnancy despite transferring 10 or more embryos in total is a condition called “recurrent IVF failure.” However, when the changing embryo transfer numbers in the last 3 years are evaluated, if only one embryo is transferred, 4 unsuccessful IVF applications or more than 2 unsuccessful IVF treatment methods with 2 high quality blastocyst transfers are considered recurrent IVF failures.
First of all, for pregnancy to occur and the embryo to attach, the signals coming from the embryo and the signals sent by the uterus must be compatible with each other. Even if there is a very small break in the molecule, attachment may not occur. It is not possible to examine or test such situations. The attachment of the embryo to the uterus is a matter of chance that we can call “random”. And it mostly involves a mysterious process. The sperm fertilizes and the egg is fertilized. When these two abilities are considered, it is understood that the effects of these two gamete cell-based problems on the quality of the embryo are very definite. However, even if the embryo quality is very very good, even if the embryo is genetically very good, it is possible that attachment does not occur or even if it does, it is weak and causes miscarriage. The fact that it can be concluded has led all scientists to focus on implantation. Implantation means attachment and has led to discussions on embryo selection conditions.
There are two points being focused on today. The first is the studies related to sperm preference, and the second is the points related to implantation, or adhesion. The fact that multiple births occur from 3rd quality embryos where the best quality embryos do not adhere, shows how short the paths covered scientifically are. Mostly, the fact that women who are considered impossible to get pregnant can become pregnant can be an example of this. For this reason, it will be realistic and healthy for people to have this awareness, and it can prevent disappointment for in vitro fertilization. The most important balance for embryos to adhere is to prevent the disruption of the estrogen and progesterone hormone balance, which is a subject of common opinion.
In IVF, due to the fact that the ratio changes towards estrogen, it is definitely recommended to take progesterone support after embryo transfer and it is recommended to take it more if needed. Apart from these two basic hormones, there are many factors that cause implantation failure.
Embryo transfer is also very important for the healthy implantation of embryos. If the transfer methods are not performed in healthy ways, implantation will not occur. Or it is possible that it will be defective. One of the biggest obstacles to implantation is the problems that can occur in the uterus such as adhesion, myoma , polyp, infection and foreign substance residues. The existence of such reasons are the reasons that can prevent the embryo from implanting. Possibilities such as defective implantation or lack of implantation will occur. In rare cases, embryos transferred into the uterus can go to the tubes and get stuck there. This can also constitute an obstacle as a problem called ectopic pregnancy . It can be called Improper Implantation.
In order for embryo attachment to be healthy, uterine contractions must occur upwards. If this does not happen, there is a possibility that the embryo will move outside the attachment site. Another important issue is that if resistance is detected in the vascularization under the endometrium, which is the inner wall of the uterus, attachment will not occur. If this is not detected, all the work may be in vain. Since detecting resistance in the uterine sub-endometrial vascularization is a difficult task, it has not become widespread in use.
Another problem is the problems that occur in the vascularization after the implantation. Since this situation is not monitored, the person can be given baby aspirin and low molecular weight heparin drugs after the embryo transfer to prevent the defective vascularization. Embryo implantation is affected by almost 40 variables. In addition to these, if it is known that it occurs with thousands of molecular processes, it can be understood how difficult it is to explain the reasons when pregnancy does not occur.
Why Does IVF Not Work?
The stages of a baby's formation are comprised of events that are too complicated to be explained by a single variable. It is not possible to talk about a single mechanism that can be explained. Candidates who have problems with IVF failure should be evaluated from a broader perspective and subjected to detailed examinations before starting a new treatment.
Primary Causes:
The genetic structure of the embryo that will enable the baby to form is defective,
Inappropriate drug protocols applied during egg development,
Inadequate culture environments in which the embryo develops,
Embryo-related factors such as thickening of the embryo's outer membrane prevent the IVF from taking hold.
Secondary Causes:
Congenital uterine problems affecting the endometrium, the inner wall of the uterus,
Polyps, myomas, and formations in the uterus that prevent the embryo from attaching
Adhesions resulting from previous infections or abortions, Coagulation dysfunctions that affect the embryo's ability to attach and grow in the uterus,
Genetic or immunological (defense mechanism) disorders that occur later in life in women are among the factors that can prevent a developing embryo, even if it is of high quality, from attaching and growing.
Tertiary Causes:
Chocolate cysts, also known as endometriosis, are a common condition encountered in expectant mothers who have difficulty conceiving.
Blockage and swelling of the tubes (although treatable, may prevent having a baby)
Hydrosalpinx, which commonly occurs after previous infection in the tubes or previous abdominal surgery.
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