New set of guidelines for Preimplantation Genetic Diagnosis Screening

The European Society of Human Reproduction and Embryology (ESHRE) has published a set of guidelines for best practice Preimplantation Genetic Diagnosis (PGD)/Screening (PGS) to give information and guidance to potential and existing PGD centres.

The four guidelines include one outlining the organisation of a PGD centre and three relating to the methods used: amplification-based testing, fluorescence in situ hybridisation (FISH)-based testing and polar body/embryo biopsy.

"The guidelines are a detailed update to the Consortium's initial PGD guidelines, published in the same journal in 2005. They have been developed as a set which, taken together, form a complete best-practice compendium," said Gary Harton, chairman of ESHRE's PGD Consortium and Head of Molecular Genetics at Reprogenetics in Livingston, New Jersey.

The rapid development of new technologies, the evolution of current methods and in light of recent advice from ESHRE on how best practice guidelines should be written, the PGD Consortium believed it necessary to update the existing guidelines.

The first guideline on the organisation of a PGD centre includes the basic requirements of an IVF/PGD centre, transport PGD (when the gametes and embryos to be tested are in a different centre than the patient), inclusion/exclusion criteria for patients, staffing, genetic counseling and accreditation of a centre.

The three more technical guidelines additionally cover laboratory requirements, clinical protocols and follow-up recommendations after diagnosis for each of the PGD methodologies: amplification-based testing, FISH-based testing and polar body/embryo biopsy.

The guidelines on amplification-based and FISH-based testing also outline quality control and quality assurance and the diagnostic confirmation of untransferred embryos. Freezing of embryos after biopsy is covered in the fourth guideline on the use of embryo biopsy in PGD/PGS.

Pre-implantation genetic screening (PGS) has been included in all guidelines. Although current evidence suggests it may be ineffective at the embryo cleavage stage using current technology, PGS may still show improved delivery rates if used at the blastocyst stage or on polar bodies. The ESHRE group decided deliberately to include PGS recommendations to assist every professional in the reproductive field to develop the best laboratory and clinical practice possible.