Genetic Solutions > PGT-A

PGT-A Preimplantation Genetic Testing for Aneuploidies

Improves the chances of reproductive success by selecting chromosomally normal embryos

Overview

PGT-A
Benefits
Indications
Embryo mosaicism

What is PGT-A?

PGT-A (formerly PGS) is a genetic test performed on embryos to identify numerical chromosomal abnormalities (aneuploidy).
Our PGT-A uses Next-Generation Sequencing (NGS), which allows us to analyze all 24 chromosomes. Chromosomal abnormalities are detected prior to embryo transfer to enable informed decisions and increase pregnancy success.

Clinical Outcome with and without PGT-A based on SART 2016 public database

SART 2016 (https://www.sartcorsonline.com/rptCSR_PublicMultYear.aspx?reportingYear=2016)

What is the procedure?

Why use PGT-A Preimplantation Genetic Testing for Aneuploidies?

Increases pregnancy rates per transfer:
Selecting normal embryos can increase the pregnancy chances after transfer
Reduction in miscarriage rate:
In the general population, 25% of all clinical pregnancies end in miscarriage, the vast majority of which are due to aneuploidy
Increase in the likelihood of having a healthy baby:
Some pregnancies with chromosomal anomalies can give rise to the birth of baby with a serious illness
Reduction in time and necessary resources:
The time and resources necessary to achieve a pregnancy are reduced
Reduces risk of multiple pregnancy:
A SET significantly reduces the likelihood of a twin pregnancy

Why Igenomix PGT-A?

Superior reviews

Independent studies have compared PGT-A from Igenomix and other labs and the highlights include:

*ABSTRACT – ASRM 2018: A comparison of diagnostic results of Preimplantation Genetic Testing for Aneuploidy (PGT-A) from reference laboratories during a period of transition; trends and inherences for patient care. D. Ioannou, M. D. Baker, S. D. Jones, l. R. Grass, K. A. Miller. Embryology, IVF Florida Reproductive Associates, Margate, FL.

**POSTER – PGDIS 2019: Clinical comparison of two pgt-a PLATFORMS UTILIZING DIFFERENT THRESHOLDS TO DETERMINE PLOIDY STATUS. D. Monahan, G. Harton, D. Griffin, M. Angle, C. Smikle. Laurel Fertility Care, San Francisco, CA.

Smart PGT-A

By applying the unique Smart PGT-A technology, Igenomix is able to constantly refine and improve our ability to analyze embryo samples. Wehave developed a proprietary bioinformatic calling algorithm based on over 100,000 embryo samples which minimizes human errors and bias/subjectivity.

Igenomix Mitoscore

MitoScore is a mitochondrial biomarker developed by Igenomix, which gives us an indicator of the energy status of an embryo.

MitoScore allows us to select those embryos with the greatest probabilities for implantation that are more likely to result in a viable pregnancy through IVF/ PGT-A.*

*(Diez-Juan et al. 2015)

Most DNA is in chromosomes within the nucleus, but mitochondria have their own DNA. This genetic material is known as mitochondrial DNA or mtDNA.
mtDNA in an embryo is an index of energetic stress, which can be used to predict its implantation potential.
Our studies indicate that an increase in the mitochondrial DNA in the embryo is indicative of an insufficient level of energy and a low implantation potential.

Who should use PGT-A?

PGT-A is particularly important for female patients over age 35, as aneuploidy rate increases with maternal age. Women under 35 have a uniform aneuploidy rate below 40%, while women above 42 have a uniform aneuploidy rate above 70%.
PGT-A can greatly reduce the odds of a patient having multiple pregnancies by providing information to select the best embryo for an elective Single Embryo Transfer or SET.

Test limitations

PGT-A does not test for:

Birth defects
Inherited single gene disorders, such as cystic fibrosis or Tay-Sachs disease
Multifactorial conditions, including autism
Adult-onset conditions such as diabetes or Alzheimer´s disease
Physical and mental traits, such as intelligence or athleticism
Microdeletions/microduplications

As with most tests, PGT-A has some limitations:

1. Accuracy is ~98%

False positive: There is a small chance an embryo could be excluded unnecessarily
False negative: There is a small chance that an embryo diagnosed as normal could still be chromosomally abnormal

2. PGT-A tests only the samples produced by embryo biopsy, not whole embryos

3. PGT-A does not detect structural abnormalities that do not involve gains or losses of genetic material. Additionally, the following cannot be detected:

Chromosome losses/gains bellow 10Mb,
Low level of mosaicism (<30%)
Uniparental disomy (UDP)
Defects affecting the complete set of chromosomes (haploidy, triploidy)

Follow-up prenatal testing is recommended to confirm the results of PGT-A.

There is a chance of unforeseeable problems with transportation, such as weather and air travel issues, or other circumstances beyond the control of Igenomix that may delay the reporting of results.

In a small percentage of cases, genetic testing cannot be performed due to improper biopsy techniques, loss of biopsied cells, or poor DNA quality.

Embryonic chromosomal mosaicism has been one of the most debated topics in the ART community for the past few years.

Mosaicism occurs randomly and spontaneously during embryonic development. During the process of cell division, the chromosomes may not distributed equally, diving rise to cells with an abnormal number of chromosomes.

Based on our internal validation of PGT-A using NGS, an embryo will be considered mosaic when the level of aneuploidies detected in the biopsy is greater than 30% and less than 70%.

The embryos will be considered to have “low-level mosaicism” if the level of aneuploidies in the biopsy is between 50% and 70%.

Embryos reported as low-level mosaicism have been shown to have significant reproductive potential.

Whereas some studies suggest that they may have lower implantation rates and higher risk of miscarriage (Viotti et al., 2021), our non-selection study has shown similar clinical outcomes tan euploid embryos (Capalbo et al.,2021).

The recently published PGDIS Position Statement on the transfer of Mosaic Embryos 2021 considers the transfer of low mosaic embryos a relatively safe option for the offspring (https://pgdis.org/docs/PositionStatement.pdf).

The risk for mosaicism to persist throughout pregnancy or until birth is thought to be low.

Embryos reported as high-level mosaicism may have some reproductive potential but with lower implantation rates and higher risk of miscarriage in comparison with euploid and low-level mosaicism embryos.

The decision on which embryos to transfer is made by the patient and the doctor.

Documentation

PGT-A Specialists’ documents

Capalbo et al., Mosaic human preimplantation embryos and their developmental potential in a prospective, non-selection clinical trial. Am J Hum Genet. 2021 Dec 2;108(12):2238-2247.

García-Pascual et al., Optimized NGS Approach for Detection of Aneuploidies and Mosaicism in PGT-A and Imbalances in PGT-SR. Genes 2020 Jul; 11(7):724.

Rodrigo et al., Characteristics of the IVF Cycle that Contribute to the Incidence of Mosaicism. Genes 2020 Oct; 11(10):1151.

Rubio et al: In vitro fertilization with preimplantation genetic diagnosis for aneuploidies in advanced maternal age: a randomized, controlled study. Fertil Steril. 2017 May;107(5):1122-1129.

Yang Z, Liu J, Collins GS, Salem SA, Liu X, Lyle SS, et al. Selection of single blastocysts for fresh transfer via standard morphology assessment alone and with array CGH for good prognosis IVF patients: results from a randomized pilot study. Mol Cytogenet 2012 May 2; 5(1):24.

Coates A, Kung A, Mounts E, Hesla J, Bankowski B, Barbieri E, Ata B, Cohen J, Munné S. Optimal euploid embryo transfer strategy, fresh versus frozen, after Preimplantation Genetic Testing for Aneuploidies with next generation sequencing: a randomized controlled trial. Fertil Steril. 2017 Mar;107(3):723-730.e3.

Coates A, Bankowski BJ, Kung A, Griffin DK, Munne S. Differences in pregnancy outcomes in donor egg frozen embryo transfer (FET) cycles following Preimplantation Genetic Testing for Aneuploidies (PGT-A): a single center retrospective study. J Assist Reprod Genet. 2017 Jan;34(1):71-78.

Viotti et al., Using outcome data from one thousand mosaic embryo transfers to formulate an embryo ranking system for clinical use. Fertil Steril. 2021 May;115(5):1212-1224.

Leigh et al., PGDIS position statement on the transfer of mosaic embryos 2021. Reprod Biomed Online. 2022 Mar 20;S1472-6483(22)00150-X.

Goldwaser, Tamar et al. Cell-free DNA for the detection of fetal aneuploidy. Fertility and Sterility, 2018; 109, 2, 195 – 200.

Kuznyetsov V, Madjunkova S, Antes R, Abramov R, Motamedi G, Ibarrientos Z, et al. Evaluation of a novel non-invasive preimplantation genetic screening approach. PLoS ONE; 2018; 13(5): e0197262.

Munné S, Status of preimplantation genetic testing and embryo selection. RBMO. 2018; 37(4):393-396.

Levy et al., Prenatal diagnosis by chromosomal microarray analysis. Fertility and Sterility, 2017; 109, 2, 201–212.

Ottolini C. et al., Scientific Reports. Tripolar mitosis and partitioning of the genome arrests human preimplantation development in vitro, 2017;7:9744.

Munné, Santiago et al. Mosaicism: “survival of the fittest” versus “no embryo left behind”. Fertility and Sterility, 2016; 105, 5, 1146 – 1149.

Bolton et al., Mouse model of chromosome mosaicism reveals lineage-specific depletion of aneuploid cells and normal developmental potential. Nature Communications, 2016; 29;7:11165.

Cimadomo D. et al, The Impact of Biopsy on Human Embryo Developmental Potential during Preimplantation Genetic Diagnosis. Hindawi, 2016, 7193075.

Scott RT, Galliano D., The challenge of embryonic mosaicism in preimplantation genetic screening. Fertility and Sterility, 2016; 105, 5.

McCoy RC, Demko ZP, Ryan A, Banjevic M, Hill M, Sigurjonsson S, et al. Evidence of Selection against Complex Mitotic-Origin Aneuploidy during Preimplantation Development. PLoS Genet, 2015; 11 (10): e1005601.

Kung A. et al., Validation of next-generation sequencing for comprehensive chromosome screening of embryos. Reproductive BioMedicine, 2015; 1472-6483.

Greco E, Minasi MG, Fiorentino F. Healthy Babies after Intrauterine Transfer of Mosaic Aneuploid Blastocysts, N Engl J Med, 2015; Nov 19;373(21):2089-90.

Yang Z et al., Selection of single blastocysts for fresh transfer via standard morphology assessment alone and with array CGH for good prognosis IVF patients: results from a randomized pilot study., 2012, 5:24.

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PGT-A Preimplantation Genetic Testing for Aneuploidies

Improves the chances of reproductive success by selecting chromosomally normal embryos

Proprietary Artificial
intelligence algorithm

98% accuracy

Superior reviews from
independent studies

What is PGT-A?

Clinical Outcome with and without PGT-A based on SART 2016 public database

What is the procedure?

Why use PGT-A Preimplantation Genetic Testing for Aneuploidies?

Why Igenomix PGT-A?

Who should use PGT-A?

Test limitations

Clinical Sheets

Brochure

Instructions

FAQs

Can we help you?

Igenomix and fertility

ERA

PGT-A Preimplantation Genetic Testing for Aneuploidies

Improves the chances of reproductive success by selecting chromosomally normal embryos

Proprietary Artificial intelligence algorithm

98% accuracy

Superior reviews from independent studies

What is PGT-A?

Clinical Outcome with and without PGT-A based on SART 2016 public database

What is the procedure?

Why use PGT-A Preimplantation Genetic Testing for Aneuploidies?

Why Igenomix PGT-A?

Who should use PGT-A?

Test limitations

Clinical Sheets

Brochure

Instructions

FAQs

Can we help you?

Igenomix and fertility

Other services

ERA

Igenomix is in the media

Proprietary Artificial
intelligence algorithm

Superior reviews from
independent studies