AI Embryo Selection vs PGT-A: How to select the best embryo for transfer?

During the IVF treatment, to increase the embryo implantation success rate, fertility specialists recommend embryo screening before embryo transfer to lower implantation failure rate. Common embryo screening methods included Preimplantation genetic testing for aneuploidy (PGT-A or PGS), Preimplantation genetic testing for monogenic disorders (PGT-M or PGD), and AI embryo selection, which assists in observing the developmental trends of embryos. The distinctions between AI embryo selection and PGS are analyzed in detail.

Is embryo screening necessary?

In the IVF procedure, besides administering ovulation-stimulating injections, eggs retrieving, and fertilizing, the quality of embryos also affects the success rate of implantation. The quality of embryos is related to whether their chromosomes are normal. Regardless of whether the embryo is male or female, it must have a complete set of 23 pairs of chromosomes.

If the embryo’s chromosomes have missing segments or are unpaired, it will affect the embryo implantation success rate. Even if the embryo successfully implants, the baby with chromosomal condition may have congenital disorders such as Down syndrome, Turner syndrome, Klinefelter syndrome, Edwards syndrome, and Patau syndrome. Therefore, embryo screening plays a crucial role in the IVF procedure.

How does PGS work?

Preimplantation genetic testing for aneuploidy (PGT-A, formerly known as PGS), is a chromosomal analysis performed before embryo transfer in the IVF treatment. It can diagnose chromosomal aneuploidies (such as Down syndrome, Turner syndrome, Klinefelter syndrome, Edwards syndrome, Edwards syndrome,  etc.) or large segment deletions (such as Prader-Willi syndrome, Cri-du-chat syndrome, DiGeorge syndrome, Angelman syndrome, etc.) that cause congenital disorders.

PGT-A technique requires culturing fertilized eggs for 5 days until they reach the blastocyst stage. Then, 3 to 5 cells are extracted from the outer layer of the embryo, known as trophectoderm cells, for chromosomal analysis. However, in some cases, eggs may not develop into blastocyst in vitro, and the PGT-A procedure may not be applicable for cases with a low number of embryos.

PGT-A is suitable for the following individuals:

• Women aged 38 and above
• Those with a history of recurrent miscarriages
• Individuals with recurrent implantation failure
• Those with a family history of chromosomal abnormalities or translocations
• Couples aiming to avoid embryos with chromosomal abnormalities
• Patients with genetic disorders

PGT-A does have limitations, as the analysis of trophectoderm cells may not perfectly represent the chromosomal status of the inner cells of the embryo. Therefore, pregnant women are still advised to consider amniocentesis for further evaluation.

How does AI embryo selection work?

AI embryo selection

By integrating dynamic imaging data of early embryo development with AI deep learning modules, the Artificial Intelligence Embryo Imaging Dynamic Analysis System has been successfully developed. This intelligence computational system assisted in predicting the appearance and chromosomal aneuploidy of embryos, providing an embryo grading system. In simple terms, AI Embryo Selection analyzes the dynamic growth changes of embryos to predict the possible chromosomal variations and identify higher-quality embryos, thereby increasing the success rate of IVF. The AI Embryo Selection offers a new option for cases in which PGT-A cannot be performed and serves as an auxiliary tool for evaluating embryo quality.

Notably, in 2021, Dr. Chun-I Lee from Lee Women’s Hospital published the AI Embryo Selection research. Dr. Lee and his team utilized a database containing over 140,000 time-lapse images of embryos, along with embryo images undergoing PGT-A, as the basis for their AI deep learning model. This AI model evaluates candidate embryos with excellent chromosomal conditions from a morphological perspective using big data analysis to determine the embryos most likely to successfully implant in the uterus.

Advantages of AI Embryo Selection

• Assists in improving the success rate of single embryo transfer

Can AI Embryo Selection replace PGS?

AI Embryo Selection utilizes dynamic imaging data of embryos and applies. AI big data precision calculations to assist in predicting and evaluating embryo quality. It is essential to note that AI Embryo Selection and PGS use different approaches for embryo quality screening, making them not directly comparable. However, both techniques can help assess embryo quality and increase the chances of successful embryo implantation.

The precision of AI Embryo Selection technology is closely related to the imported data used for calculations. In Lee Women's Hospital, besides utilizing the built-in database provided by the Time-lapse system, clinical databases are incorporated into the Embryo Selection system through research. The hospital performs over 4,000 cycles of assisted reproductive treatments annually, accumulating a vast database of over 30,000 successful IVF babies. With almost 40 years of experience in reproductive medicine, Lee Women's Hospital is well-equipped to cater to the needs of infertile couples in domestic IVF treatments.