+90 539 121 02 42
We are available 24/7
Email Us Now
[email protected]

New Generation PGT For Incredibly Improved IVF Outcomes 

Next-Generation Sequencing or NGS is part of in-vitro fertilization and uses the most advanced techniques of human genome sequencing to test embryos. This form of “reading the embryo’s genetic information” opens an entirely new world of diagnostic possibilities as it provides details about the embryo’s DNA for genetic mutations or diseases. You may hear it referred to as PGD-NGS (preimplantation diagnosis base on next-generation sequencing) and gives physicians and fertile experts a unique opportunity to help couples with hereditary disorders or genetic abnormalities to NOT pass them on to their offspring.


What is so special about NGS?

To begin with, PGS-NGS comes with extraordinary precision and sensitivity. Plus, the test design is tailored to your particular needs and requirements. In detail, we can use this method to test all 24 chromosomes at the same time with 99.99% accuracy, which is, indeed, unprecedented. Also, any imprecision in a reading does NOT affect the results of the test whatsoever, unlike with other techniques, such as aCGH, where each chromosome is counted at around 10-12 times or so. Plus, it gives us the chance to test an impressively long range of monogenetic diseases with known genetic backgrounds.

To be more analytical, NGS:
Improves embryo safety – NGS reduces the number of required biopsies for the diagnosis. In most cases, only a single embryo biopsy is enough for a reliable result. Until now, these biopsies and tests had to be repeated in the majority of cases.
Multi-test possibility – Gives the opportunity to combine single-gene (monogenic) diseases and chromosomes tests in a single test. This was not possible in the past. Now, we can, for example, test for both monogenic disorders and chromosomal aneuploidy with a single embryo biopsy.
Reduced test costs – Due to the special design of the PGM apparatus, we are able to provide more cost-effective tests compared to existing methods.
Comprises the basis of all other techniques – The reference method is DNA sequencing, primarily because it is directly related to the reading of the genetic material. The change markers of other techniques, such as microarrays and FISH, indirectly test the genetic material. These methods also require the use of advanced optics (light), which not always provides us with reliable results (they are prone to failure). For that reason, NGS is considered to be referential for all other known methods to date.
Has impressive credibility – The method enables us to make a direct connection of the obtained information with the DNA, and, since each sample is assigned an extra molecule code as soon as the material is collected from the embryo, the error possibility is next to zero.
PGS-NGS gives 99% chance for healthy childbirth – Although each case is different, the technique provides an incredibly high percentage of giving birth to a healthy child. However, it all depends on the number of healthy embryos, as well as the course of pregnancy and the health condition of the patient. Using the test enables us to determine whether one is at risk of developing a genetic disease or healthy. NGS is the only diagnostics solution that allows us to detect DNA abnormalities at a remarkably early stage of development.
It covers a huge range of abnormalities that can be diagnosed with a single procedure – A standard diagnosis covers all 22 chromosomes plus the two sex chromosomes (Y and X) and is performed for chromosome number abnormalities (aka aneuploidies). In the majority of cases, these abnormalities can lead to the death of the embryo while others cause Patau, Edwards, Turner, Down, or Klinefelter syndromes, or other serious genetic defects. The same technique is used for screening single-gene mutations.
NGS is an extremely sensitive technique – Other methods allow the analysis of only several dozen points on a chromosome. They also require in-depth knowledge of the target sequence. This means that they give us considerably less information. The NGS analysis includes several hundred thousand readings per chromosome while performing the analysis of a single DNA fragment several hundred times. Besides, reading each gene that impressive number of times minimises the risk of misreadings compared to other methods where the genes are read only a dozen times at the most. As a result, we receive extremely accurate and reliable results.

What are the stages of NGS?

As already mentioned, NGS diagnostics is part of the IVF process. The steps followed are the same as with using PGT or PGS for IVF and are described below:


The female patient undergoes hormonal stimulation to make the ovaries produce more eggs.


We collect the eggs and prepare them for fertilisation.


Our embryologists collect cells from the eggs and combine them with the male partner’s sperm (or donor sperm, depending on the case).


We leave the developing embryos to reach the Day-5 stage (aka blastocyst stage), and then the embryologist samples them for testing.


The biopsied samples are sent to our highly sophisticated Molecular Biology Lab, where they are analysed (we perform an analysis of trophectoderm cells, among others).


The embryos that bear no hereditary abnormalities are selected for transfer to the female patient’s uterus.


7) Depending on the case, the blastocyst embryos from which the material has been collected for the purpose of testing for chromosome number abnormalities need to be frozen*.

Freezing embryos that are not used in IVF allows couples to avoid going through the ovarian hormonal stimulation stage again, which reduces the cost of the entire procedure considerably. It is even possible to perform a detailed and in-depth diagnosis of frozen embryos without having diagnosed their genetic background first.

Important Note:

Unlike with other methods, NGS does not harm the embryos. According to the guidelines of the ESHRE (European Society of Human Reproduction and Embryology), only embryos of good quality should be used to collect material from. It is paramount that the collected material for testing is of diagnostic quality. ESHRE also dictates that the remaining cells must have excellent chances of further development. This means that embryos without the appropriate morphology or of poor quality do not qualify for biopsy and further testing.

Aneuploidy - Its major contribution to unsuccessful IVF

Aneuploidy is one of the primary causes of unsuccessful IVF cycles and extremely common in human embryos. Aneuploid embryos may miscarry during pregnancy, not implant after they have been transferred to the woman’s uterus, or arrest while still in culture. One of the screening strategies that help identify chromosome abnormalities in embryos which have been created via IVF is PGT-A (preimplantation genetic testing for aneuploidy).

Selecting chromosomally normal embryos for the transfer is, theoretically, associated with enhanced implantation rates, which also lead to improved pregnancy rates per transfer. For that reason, more than 20% of all IVF cycles include PGT-A in the USA and other countries abroad. Next-generation sequencing (NGS), on the other hand, is found to be a much more effective method to detect aneuploidy than any other technique so far, which is related to improved pregnancy outcomes.

How NGS Helps with Aneuploidy Detection

Studies investigating the impact of the change in aneuploidy detection technique in STEET (single-thawed euploid embryo transfer) cycles found that PGT-A demonstrates a dramatic increase when NGS is used when it comes to live birth and ongoing pregnancy rates. This is attributed to the fact that NGS helps identify embryos with reduced viability (i.e., those potentially classified as normal incorrectly, with segmented errors, or mosaic abnormalities) considerably. NGS now allows us to find such embryos more accurately. This means that fewer clearly euploid embryos are available for storage, which, in turn, improves both live birth and ongoing pregnancy rates.
Simultaneously, it has been evidenced that NGS also contributes to a reduction in biochemical pregnancy rates. Biochemical pregnancy is when the woman gets a positive pregnancy test but, in reality, shows no evidence of either an extra uterine or ultrasonographic pregnancy. Studies have found that embryos carrying chromosome abnormalities (i.e., smaller segmental errors or low-level mosaicism) may as well go stealth (remain undetected) by other techniques, such as aCGH. So, they may implant successfully, but it will be short-lived, leading to biochemical pregnancy. 
Switching to NHS enables us to identify such embryos more easily so we can exclude them from the transfer phase of IVF. Thus, reducing biochemical pregnancy rates. 

When it comes to miscarriages, the fact that NGS helps reduce the number of embryos that can be stored is potentially related to the more accurate identification of embryos that consist of combinations of both chromosomally abnormal and normal cell lines (aka diploid-aneuploid embryos). It has been demonstrated that such embryos have a lower implantation rate and a higher miscarriage rate than those with only euploid cells. Not clearly euploid embryos are associated with abandoned transfers although in some cases, they might lead to chromosomally normal live births. So, if after NGS, an embryo is characterized as mosaic, we seriously doubt its candidacy for transfer.

Truth be told, the evolution of genetic methods is steadily contributing to improved IVF outcomes. This has to do with the capacity of PGT-A to enhance these outcomes. To date, NGH is the most advanced technique to help distinguish viable embryos from those with no or little ability to lead to a healthy pregnancy with impressive accuracy.
With an extensive aftercare programme, Cyprus IVF Clinic are ready to handle your every fertility need. Whatever your circumstances, please contact us today for advice and guidance on making the move towards IVF.
© Copyright 2022 | Cyprus IVF Clinic powered by EURO IVF | All Rights Reserved
envelopephone-handsetmap-marker linkedin facebook pinterest youtube rss twitter instagram facebook-blank rss-blank linkedin-blank pinterest youtube twitter instagram