What is NGS?
NGS (Next Generation Sequencing) is the latest and most comprehensive chromosome screening technology applied to detect numerical chromosomal abnormalities (chromosomal abnormalities) of embryos.
This method allows rapid and efficient genetic analysis of embryos obtained by in vitro fertilisation, and the selection of normal embryos to be transferred. As a result, pregnancy success per transfer increases significantly and miscarriage rates decrease.
One of the main reasons why a healthy pregnancy cannot be achieved despite the successful transfer of embryos obtained in IVF treatments to the uterus is chromosomal abnormalities in the embryos.
Our next-generation sequencing technology allows the examination of all 24 chromosomes (universal chromosome screening). Embryos with chromosomal defects can be detected before they are transferred to the mother’s womb, and the chance of pregnancy increases by transferring normal embryos.
Pregnancy rates of less than 20% can be obtained by transfer of an embryo that has not been genetically screened with NGS in women over the age of 40, while pregnancy rates approaching 40-50% can be obtained by transfer of an embryo diagnosed as chromosomal normal with NGS.
Who Should Have the NGS Test?
We recommend the NGS method especially to our patients over 35 years of age. The rate of genetically unhealthy embryos increases with the age of the mother. While this rate is less than 40% for women under 35, this rate is over 70% for women over 42.
Especially in patients with recurrent miscarriages, in expectant mothers over 40 years of age, in infertility of unknown origin, in couples with structural chromosomal problems such as translocation and inversion, severe male infertility, NGS method is the best to be used for having healthy embryos which being tested in all chromosomes.
The use of the NGS method in patients who are definitely not considering multiple pregnancies guides us in identifying the appropriate embryo and selecting the best embryo. In this way, you can reduce the risk of multiple pregnancies.
How is NGS Method Done?
NGS-based PGD is applied to embryos that have reached the blastocyst stage. An embryo biopsy for NGS is performed by removing only a few cells from the trophoblast cells of an embryo that has reached the blastocyst stage. Embryos are evaluated as chromosomal by genetic analysis performed in these cells.
The embryo reaches the blastocyst stage, at the earliest, on the fifth day after oocyte collection. In cases such as advanced maternal age and severe male infertility, the growth rate of the embryos may slow down and the growth of the blastocyst may reach 6-7 days after egg collection. Slow growth does not increase the risk of chromosomal disorders in embryos, and at this stage, the quality of embryo development is more important.
The biopsy applied to the embryos is performed under a microscope with special techniques and by trained embryologists. The procedure is short and does not harm the embryo. The embryos from the biopsy are then frozen one by one by vitrification. Less than 5% of all embryos may experience partial loss of viability or complete disruption after freeze-thaw.
Published studies have not shown an increased incidence of birth defects in pregnancies leading to delivery after biopsy and freeze-thaw procedures, compared to pregnancies transferred without embryo biopsy that led to delivery.
NGS Test Advantages and Powerful Features
- Increases Pregnancy Rate Per Transfer
Selecting embryos with normal chromosomes increases the pregnancy rate after transfer.
- The Accuracy Rate Is Better Than Other Genetic Tests
Low rate of false positives or false negatives less than 5%. In comparative studies with Array cGH (Harmonic Genetic Screening), NGS was found to have a higher accuracy rate
- Low Rate Reduction
In all patient groups, 25% of pregnancies result in miscarriage. If an embryo with a normal genetic structure is transferred, the risk of miscarriage is reduced.
- Increase Your Chances Of Having A Healthy Baby
Some pregnancies may result in the birth of a child with the chromosomal syndrome, causing serious health problems.
- Saves Time and Money
The time required to achieve a healthy pregnancy is shortened.
- Reduces Risk of Multiple Pregnancy
Patients may choose to transfer a single normal embryo instead of multiple undescended embryo transfers to reduce the risk of multiple pregnancies.
- Ensures Correct Fetus Identification
This method can measure the amount of mitochondrial DNA that provides energy for the cell and allows the identification of the strongest embryo.
- A Comprehensive Examination Of All Chromosomes That Make Up The Fetus
In the NGS method, mosaicism that can develop in embryos can be detected, and at the same time, chromosomal anomalies (translocations, inversions, and deletions) can be detected with all chromosomes.
- Protects From Psychological Traumas
Negative results in IVF treatments stress the family psychologically. With the identification of a healthy embryo, the chance of pregnancy increases.
- Gender Can Be Selected Using NGS
Since it provides information about all the chromosomes in the embryos, it allows for sex selection