Table 2 PGDIS recommendations for the clinician [15]

1. Patients should continue to be advised that any genetic test based on sampling one or small number of cells biopsied from preimplantation embryos cannot be 100% accurate for a combination of technical and biological factors, including chromosome mosaicism.

2. The patient information and consent forms for aneuploidy testing (if used) should be modified to include the possibility of mosaic aneuploid results and any potential risks in the event of transfer and implantation. This needs to be explained to patients by the clinician recommending the aneuploidy testing.

3. Transfer of blastocysts with a normal euploid result should always be prioritized over those with mosaic aneuploid results.

4. In the event of considering the transfer of a blastocyst with only mosaic aneuploidies, the following options should be discussed with the patient:

 a. A further cycle of IVF with aneuploidy testing to increase the chance of identifying a normal euploid blastocyst for transfer

 b. Transfer of a blastocyst with mosaic aneuploidies for low risk chromosomes only, after appropriate genetic counseling if available

 c. Appropriate monitoring and prenatal diagnosis of any resulting pregnancy, preferably by early amniocentesis (14 weeks gestation).