Dear Colleague,

The 17th International conference on Preimplantation Genetics will be organized in Bangkok, Centara Grand & Bangkok Convention Centre at CentralWorld, May 3-6, 2018 (see PGDIS website www.pgdis.org).

The Scientific Program of the Conference will reflect the recent developments in preimplantation genetic testing (PGT) and prospective identification of at risk PGT couples, to extend the application of PGT technology to the patients at need both in ART and PGT.

While the developments in 24-chromosome aneuploidy testing (PGT-A) have improved the embryo selection, they have also resulted in the identification of sub-chromosomal variations and mosaicism, one of the major issues to be addressed, as there is no sufficient understanding in their biological significance and clinical impact on PGT outcome. As significant proportion of mosaicism and segmental imbalances, undetected by low resolution PGT-A methods, may survive implantation and contribute to fetal loss, the utility of this information will be further explored to update the recommendation of the previous PGDIS Position Statement on the subject, for better interpretation and proper counseling the patients with such embryo variations.

Among important aspects to address will be also the requirements for expanding testing to segmental aneuploidies that can potentially cause miscarriage and for undertaking additional testing of euploid embryos to improve the chances to implant and result in a viable pregnancy. However, these tests will further increase PGT cost, so the emphasis will be on a critical review of their utility as part of the embryo selection process. Among the candidate tests addressed will be cytoplasmic DNA contents, epigenetics and genetic expression profiles, time-lapse imaging and endometrial receptivity, the available data on which are insufficient or controversial, to make decision for their practical utility as part of PGT.

In addressing PGT for monogenic disorders (PGT-M), the emphasis will be on the possible universal PGT approaches, as an increasing number of PGT-M is presently performed combined with PGT-A, providing the WGA product for evaluation of mt-DNA copy number or any other additional test, as part of the embryo selection process. However, there are still limitations of such combine testing, requiring careful consideration.

Although with the shift of biopsy procedure to blastocyst its effect on the embryo development is minimal, its potential detrimental effect still cannot be excluded. So the prospect of the development of non-invasive approaches to PGT (NIPGT) will be explored. This will also include addressing the progress in non-invasive prenatal testing (NIPT), as a possible follow up prenatal diagnosis, still recommended after PGT.

Finally, with the recent progress in CRISPR-based gene editing, the potential utility of this technology for PGT-M will be addressed, as some patients may have a poor chance of producing unaffected oocytes/ embryos.

As usual, a number of Pre-congress Workshops will be organized, including the Annual Hands-On Workshop on PGT by Blastocyst Biopsy, April 29 - May 1, 2018 at the Istanbul Memorial Hospital PGD Center, for continued support to the shift from the cleavage stage to blastocyst biopsy, combined with novel methods for genetic testing (see the Hands-On Workshop Program).

The progress in the organization of the Conference may be followed in the PGDIS websites (www.pgdis.org), with the registration and abstract submission to be opened shortly.

We are looking forward to welcoming you in Bangkok!