Why has my good quality embryo not implanted?

If you have to turn to donor eggs to build your family, you have most likely spent hours, if not weeks or months, looking carefully at donor profiles to find the one that best fits what you are looking for to start a family. Ovobank’s donors are young, healthy women who have passed rigorous psychological, physical, gynecological and genetic tests. The donor has to go through controlled ovarian stimulation in order to obtain the eggs that will later be used for fertilization and that will become your embryos.

It is normal to expect these eggs to be of the best quality and, therefore, that the embryos produced from them will be optimal for implanting and will lead to the desired pregnancy. However, not all good quality embryos implant in the uterus. One of the most important factors in embryo implantation is the state of the endometrium; the layer of tissue that lines the inside of the uterine cavity, where the embryo attaches in order to begin the pregnancy.

Your Ovobank egg lot will arrive at your fertility clinic vitrified (frozen). On the day of fertilization, your clinic will thaw them in the laboratory and they will be fertilized with sperm (from the partner, your own or from a donor, as required). The resulting embryos will be cultured in the laboratory until they reach the blastocyst stage (5 days). During this process, the embryologists analyze and grade them according to their quality.

Embryos are graded using criteria such as: the number of cells and their symmetry, the percentage and type of cell fragmentation and the rate of embryo division, among others. The grading system from A to D can be explained as follows:

• Embryo A: optimal quality and high implantation rate.
• Embryo B: good quality and good implantation rate.
• Embryo C: average quality and implantation rate.
• Embryo D: low quality and low implantation capacity.

In general, embryologists choose embryos graded A or B, since they are the ones most likely to implant and thus achieve the desired pregnancy. If, as sometimes happens, good quality embryos are not obtained, an average quality embryo can be transferred. The remaining embryos can be frozen (vitrified) for later attempts.

What is meant by implantation failure?

If pregnancy has not been achieved after three or more cycles in which good quality embryos have been transferred, it is considered that there is implantation failure. In the case of implantation failure, it is essential to investigate the root of the problem in order to solve it before trying again, with the aim of achieving pregnancy as soon as possible.

Why can’t I get pregnant?

The most common reasons for implantation failure and for the impossibility of achieving pregnancy are usually due to embryonic and/or uterine causes. However, other factors may also be involved, such as infertility of unknown origin, which can be very difficult and complicated to diagnose.

Implantation failure due to embryonic causes with an embryo that appears to be of good quality may be due to genetic alterations, for example having an incorrect chromosomal load. This can cause a miscarriage. Preimplantation Genetic Diagnosis (PGD) can be used to study the genetic complement of the embryo (from an embryo biopsy) and try to avoid the transfer of embryos with genetic abnormalities.

If the cause of the implantation failure lies in the uterus, it could be because the endometrium is not in its optimal receptive state at the time of the embryo transfer. It is possible to freeze the embryos and carry out tests such as the Endometrial Receptivity Array (ERA test) to study when the endometrium is in the best condition to carry out the embryo transfer, and thus schedule future transfers.

At Ovobank we want to help you build your family, and we strive to offer you the best service and quality, with the shortest possible wait and competitive prices that help you to carry out the whole process. For more information about our frozen egg lots, the donor selection platform, our clinical pregnancy guarantee programs or to speak to one of our experts, get in touch today through our contact form or by email: info@ovobank.com

We will be delighted to answer all your questions!