Implantation failure

Implantation failure is diagnosed when a baby has not been achieved after at least three cycles of In Vitro fertilization (IVF) or the transfer of more than ten good quality embryos.

Currently, there are highly effective solutions for each of the causes of implantation failure, among which the transfer of embryos in the blastocyst phase (day 5 of embryonic development), preimplantation genetic diagnosis and assisted hatching (or assisted hatching).

What is the implementation failure?

Embryo implantation is a complex process that requires a healthy embryo and a receptive endometrium, as well as a close dialogue between the two.

In the field of assisted reproduction, implantation failure is diagnosed when a baby has not been achieved after at least three cycles of In Vitro fertilization (IVF) or the transfer of a total of ten good quality embryos.

Causes of implantation failure

The causes of implantation failure are multiple and both embryonic problems and problems with the uterine environment may be involved:

• Embryonic problems include chromosomal and genetic abnormalities, as well as difficulty for the embryo to emerge from the layer that surrounds it (zona pellucida) and has protected it during its development. It is necessary for the embryos to break this layer in order to implant in the uterus and produce pregnancy.
• Problems with the uterine environment may be due to anatomical alterations, inadequate endometrial development, benign tumors (fibroids), scars, adhesions, synechiae, infections or inflammations that affect its receptivity. Likewise, the presence of infectious foci near the uterus must be ruled out, which can be caused by conditions such as hydrosalpinx.
• And finally, hormonal, metabolic (insulin resistance and obesity), immunological (antiphospholipid antibody syndrome) or blood coagulation (thrombophilia) disorders that prevent implantation.

How are the causes of implantation failure diagnosed?

There are several tests that allow us to determine the causes of implantation failure:

• The blood test is useful to rule out hormonal, metabolic, immunological, and blood clotting disorders. The latter hinder the normal arrival of blood to nourish the embryo.
• The presence of uterine malformations or fibroids can be diagnosed by a gynecological vaginal ultrasound. This also allows the identification of the hydrosalpinx and can be used to measure the endometrium (inner layer of the uterus), which, according to experts, should measure 7 to 10 millimeters or more in the middle of the cycle.
• In addition to a spermiogram or semen analysis, it is advisable to carry out a sperm DNA fragmentation test before In Vitro Fertilization, particularly when there is a history of diseases that may affect the quality of the sperm.
• Chromosomal and genetic abnormalities in the embryo can be detected by preimplantation genetic diagnosis or microarrays.
• In order to establish whether it is necessary to carry out an assisted hatching process, embryonic development must be monitored after In Vitro Fertilization to determine if there is thickening of the zona pellucida once the embryo arrives. to the blastocyst stage.

It is important to note that a detailed evaluation of the cycles carried out so far (number of eggs obtained, fertilization rate, techniques used and embryonic development) is essential to establish an accurate prognosis.

Treatments to have a baby after implantation failure

Knowing the causes of implantation failure is essential when it comes to selecting a treatment that allows you to achieve a baby with the least wear and tear. Currently, there are highly effective solutions for each of these causes.

When implantation failure is associated with immunological problems, these can be easily treated with medications, while if it is due to problems with the uterine environment, treatment varies depending on the cause and can range from hormonal therapy to surgery in very specific cases. However, when implantation failure is due to embryonic problems, the main treatments include:

• The transfer of embryos in the blastocyst phase, that is, five or six days after fertilization.

Until a few years ago, all embryos were transferred on the third day after fertilization because it was impossible to keep them alive in a laboratory, but today technology allows us to culture them for a longer time, which makes it easier to select the oldest embryos. quality and with greater power of implementation. (If you want to know more about prolonged embryo culture click here)

• The Preimplantation Genetic Test for Aneuploidies (PGT-A)

This technique allows only embryos free of chromosomal abnormalities (aneuploidies) to be transferred to the mother's uterus. This is related to implantation failure, recurrent pregnancy loss and the woman's age, since as the woman progresses, the risk of presenting chromosomal abnormalities in the baby increases.

This is why transferring only embryos free of these genetic alterations allows us to maximize the chances of implantation, pregnancy and having a baby at home regardless of the woman's age.

• Assisted hatching

Before implantation in the uterus, the embryo must be freed from the membrane that surrounds it (zona pellucida) to come into direct contact with the cells of the endometrium. In some cases, implantation failure is due to the inability of the embryo to leave the zona pellucida and it is necessary to facilitate this process to increase the probability of implantation.

At Ingenes we have embryologists who are experts in micromanipulation techniques, which allows us to perform the laser-assisted hatching procedure quickly and accurately without causing any damage to the embryos.