Comprehensive Chromosome Screening (CCS)

The advantages of comprehensive chromosome screening (PGS/PGT-A/CCS) in women of an advanced maternal age

Women currently seek guidance on reproduction at a much older age than they did some years ago. As a result, amongst the women who undergo fertility treatment, there is a significant group of women of an advanced age and their prognosis is poorer. This is a huge challenge for reproduction specialists. […]

2018-09-06T09:36:01+02:007 de September de 2018|0 Comments

CCS (Comprehensive Chromosome Screening) and unexplained sterility

Any couple that turns to a fertility clinic undergoes a number of tests in order to diagnose the fertility issue that is making natural conception impossible. It is estimated that, at the end of the process, 1 in 4 couples are provided with no apparent reason for the reproduction issue. In these couples, no significant findings came up in the diagnostic tests carried out both on the male and the female partner.
Circumstances such as these generate a great deal of uneasiness and doubts in couples because, with no known reason for their infertility, they feel as if they were in no man’s land. […]

2018-03-28T10:55:25+02:006 de October de 2017|0 Comments

Should embryos with chromosomal mosaicism be rejected?

When good quality embryos do not implant correctly or lead to pregnancy loss, in vitro fertilisation (IVF) does not provide us with the results we had hoped for. This is often because the embryo is a carrier of abnormal chromosomes. Fortunately, in our clinic, we have access to the very latest in embryo chromosome diagnosis techniques such as array CGH and next generation sequencing (NGS). We can use this technology to detect abnormalities in the embryo that will cause pregnancy loss or that will lead to the birth of a child with chromosomal abnormalities such as Down’s Syndrome, also known as trisomy 21. As such, we can use these techniques to select and transfer the embryos with the greatest chance of leading to the birth of healthy child. […]

2018-03-26T17:47:29+02:0025 de August de 2017|0 Comments

Why does embryonic arrest sometimes happen during in vitro development?

Many factors can intervene in arrest processes during embryo development which mean cell division is detained and, therefore, it is not possible to implant the embryo in the mother’s uterus and bring about a pregnancy.
In the first instance, the conditions for development are essential.  Embryos that develop in vitro are subjected to a number of artificial conditions that do not exist in vivo and which will always be less than optimum. Embryos which were apparently viable can suffer embryonic arrest. Huge efforts have been made over the last few years to try and mimic what happens inside the mother and replicate those conditions in laboratory processes.  Most of all, the concentration of oxygen in incubators has been reduced, going from 20% down to 5%. The composition of the culture means has also been improved. This, along with exhaustive monitoring of pH and osmotic concentration, means that we can routinely carry out prolonged embryo development up to blastocyst stage in order to achieve improved embryo selection and increase pregnancy rates. […]

2018-03-26T18:18:33+02:0019 de August de 2016|2 Comments

Can I choose the sex of my embryos when I undergo embryo transfer?

The human genome consists of 46 chromosomes: 23 of these are inherited from our father and the other 23 are inherited from our mother. Our organism’s entire genetic make-up is stored in these chromosomes. The 23 pairs are organised as follows: 22 pairs, known as autosomes, and one pair of sex chromosomes (X and Y) which differentiate the two sexes (XY for males and XX for females).
From a technical point of view, using pre-implantation genetic diagnosis, we have the means of analysing an embryo’s entire chromosomal make-up. This technique, which is known as PGS/PGT-A/CCS (Comprehensive Chromosome Screening), means additional or a lack of any chromosomes in the embryo can be detected. Therefore, we can use PGS/PGT-A/CCS to analyse the entire make-up of the embryo and determine that there are neither DNA excesses nor deficiencies which will stop the embryo from developing properly. But, if we focus on the sex chromosomes, we can also determine if the analysed embryo has two X chromosomes and will, therefore, be a girl (XX) or one X chromosome and one Y chromosome (XY) and will be a boy. […]

2018-03-26T19:17:10+02:0029 de July de 2016|0 Comments

State of the art technology in preimplantation embryo diagnosis: Array-CGH

Preimplantation Genetic Diagnosis (PGD) is the study of chromosomal and genetic abnormalities in embryos before they are transferred to the mother’s uterus by an In Vitro Fertilisation (IVF) technique. It seeks to ensure healthy offspring and stop transmission of a given disease. […]

2016-08-04T13:13:58+02:0011 de March de 2016|0 Comments

Why does Comprehensive Chromosome Screening (PGS/PGT-A/CCS) by array-CGH reduce miscarriage rates?

Miscarriage rates in the general population with no fertility problems range around 15-20%. In other words, one out of every five couples who achieve pregnancy suffers a spontaneous miscarriage, and 5% of these couples suffer it more than once. Even when pregnancy is achieved with the help of assisted reproduction techniques, miscarriage rates do not vary. For this reason, it is important when couples come to our clinic seeking reproductive counselling to perform comprehensive testing and design an adequate protocol for their case to secure the best result, which is a healthy baby at home, minimising the chances of miscarriage. In order to do that, one should know that miscarriages and pregnancy losses are caused by different reasons (uterine problems, immunological problems, and so on), and yet in half the cases there are chromosomal abnormalities in the embryo that prevent pregnancies to progress, hence causing miscarriages. Normal embryos have two copies of each chromosome, one inherited from the father and the other from the mother, and the chromosomal anomalies they may suffer involve a change in the number of copies, producing an imbalance in their genetic load which might block embryo development. […]

2018-05-14T08:49:14+02:0012 de February de 2016|0 Comments

A revolution in genetics: next generation DNA sequencing

In the year 2000, human sequencing was achieved following 10 years of scientific work and now, thanks to next generation DNA sequencing, we are able to get to know a human genome in the space of just one week. It is still not possible, however, to access 100% of the genetic information contained within an embryo, the true origin of human life. But scientific progress is unstoppable and with this new technique a new range of promising options for genetics, for fertility and for life have opened up.
According to researchers, the possibilities which DNA sequencing offers are revolutionary and huge. Despite being at a very initial stage in which only the tip of the next generation sequencing iceberg has been uncovered, the number of uses is so varied that determining how to manage everything this technique implies will, in fact, be the future’s biggest challenge.
For the time being, thanks to human sequencing, nowadays “there is greater power of analysis and this facilitates many things and very significant possibilities”, explains the scientist and molecular biology and genetics investigator at Instituto Bernabeu, José Antonio Ortiz. The new technique, which can only be carried out in leading international clinics such as IB, “has revolutionised genetics. Genetic studies are now much quicker.’ […]

2016-08-04T13:21:22+02:005 de February de 2016|0 Comments

When will my embryos be biopsied? Why?

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. […]

2018-03-26T18:06:15+02:0015 de January de 2016|0 Comments
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