From the very moment when sperm fertilises an ova, a new embryo starts developing and a large number of cell divisions take place. This embryo development is observed in an in vitro fertilisation laboratory up until the blastocyst stage (day 5 or 6 of development). Sometimes during the cell division process, fragments of the embryo become isolated between cells that have developed correctly. These fragments come from embryo cell remains and can stop the embryo from developing correctly. One of the negative impacts consists of issues reaching the blastocyst stage and the posterior impact on implantation in the uterus. In fact, embryo fragmentation is one of the most significant characteristics used to determine embryo quality. […]
Pre-implantation genetic diagnosis (PGD) is a technique that provides a ‘genetic understanding’ of the embryo before it is transferred to the uterus. Thanks to this technique, we are able to study the embryo’s chromosomal make-up and determine if it is a carrier of a hereditary condition of any kind. This information helps us to select the embryos that will lead to the birth of a healthy child. But how do we obtain this information?
Work is currently being carried out to discover non-invasive means of gathering genetic information from the embryo but, to date, the only means is an embryo biopsy. What is an embryo biopsy? […]
It is possible to determine the gender of a future baby (embryo) before transfer takes place. In fact, this strategy has been used for many years in order to avoid the transmission of sex chromosome hereditary diseases (pre-implantation genetic diagnosis or PGD).
When the technique was in its early days, embryo analysis was carried out on day 3 of embryo development. Nowadays, it is carried out between days 5 and 7 of development (blastocyst stage). The analysis provides a simultaneous understanding of all the chromosomes in the embryo, meaning that transmission of chromosomal abnormalities can be completely eliminated. The technique has a 98% success rate. […]
During in vitro fertilisation processes, for the first few days of their lives, human embryos have to develop outside the mother’s body in special incubators. Temperature and pH conditions need to be optimum and embryos also need to have access to all the necessary ingredients in order to feed and, in doing so, meet their energy requirements. Culture media are used for this. […]
Cryopreservation, or embryo freezing, is an essential part of courses of assisted reproduction treatment since it means that embryos can be preserved in order to be used at a later date and without the passing of time having a negative impact on their viability.
Embryos obtained as a result of in vitro fertilisation (IVF) may be thawed for a number of reasons: […]
Successfully treating implantation failure and recurrent pregnancy loss is undoubtedly a challenge for doctors and for patients.
It is an area on which we continuously focus research at Instituto Bernabeu and, whilst we are far from finding a solution to all problems, the number of couples we are able to successfully treat is forever increasing.
An approach which does not take all 3 parties into account – the female, the male and the embryo – is incomplete. When evaluation only takes the couple into account, the reason behind the issue is only determined in under 20% of all cases. […]
Determining the ideal day for embryo transfer has always been a controversial issue and there are, even today, still a number of doubts surrounding this issue.
Embryo culture is, basically, a selection process. Each embryo’s progress is evaluated throughout and a decision is taken on which is most likely to implant successfully. […]
Preimplantation Genetic Diagnosis (PGD) is a tool designed to “get to know” the embryos genetically before they are transferred into the mother’s uterus. Thanks to this technique, we can study their chromosome count and find out if they are carriers of a hereditary disease. This information helps us to select the embryos that will produce healthy babies. Yet, how can we find that information?
Today, the only way to find genetic information about embryos is by performing an embryo biopsy. What does embryo biopsy involve?
To explain the biopsy procedure we should keep in mind that our point of departure is EMBRYOS. Embryos are retrieved after performing an assisted reproduction cycle, preferably by Intracytoplasmic Sperm Injection (ICSI), and their development is assessed during the culture period until day 3 or day 5. […]
During the performance of assisted reproduction procedures, the best embryo is selected for transfer into the mother’s uterus. The selection is based on the “look” of the embryo shortly before transfer. As a matter of fact, waiting time normally stretches until day 5 of embryo culture in order to enhance the potential of the selected embryo and its synchronisation with the endometrium.
Sometimes the selection is favoured by performing a Comprehensive Chromosome Screening (PGS/PGT-A/CCS) test. Thanks to this technique, we can find out if an embryo has all the chromosomes in their exact number, in other words, if it is chromosomally normal. In this way, the selection is both morphological (external look) and chromosomal (internal look).
To be able to analyse the embryo we must first biopsy it (take a cell sample) without affecting its development and subsequent implantation. Biopsy techniques have been evolving until the process has been optimised. […]
For as long as we can remember, we assume that we belong to certain standards. These standards are set based on the average population, just as children in pediatric check-ups are assessed by a percentile of height and weight. As adults we are assessed by our body mass index. In both cases, we try to reach an “average” rate.
What do we consider average?
This also happens at the embryonic stage. The process of embryo division observation is established to assess whether or not embryos are normal. This observation should be performed at specific times, so that each embryo is observed and evaluated daily.