Cytogenetic and Microarray Analysis Follow-Up of PGT-A Mosaic and Sex Discrepant Embryos During Pregnancy: Absence of Confirmation and Follow-Up Recommendations.

OBJECTIVES

The objective of this study was to examine the concordance of results between mosaic pre-implantation genetic testing for aneuploidy (PGT-A) and diagnostic testing in resulting pregnancies conceived by IVF with PGT-A.

METHODS

This study retrospectively provides analysis of 328 patients ascertained due to a mosaic PGT-A finding and 25 with a discordant reported sex, studied prenatally, utilizing standard karyotype and/or SNP microarray analysis.

RESULTS

None of the 328 mosaic PGT-A findings were confirmed by the diagnostic prenatal studies with karyotype and/or microarray analysis. Additionally, of the 298 prenatal microarray studies performed, five demonstrated pathogenic abnormalities (1.7%) that were unrelated to PGT-A referral. Thirty-four of these cases were also studied to determine if UPD occurred; all were biparental.

CONCLUSIONS

This work emphasizes the importance of PGT-A follow-up and demonstrates that the vast majority will have normal diagnostic results and only a small number will be confirmed using prenatal diagnostic analysis. This work also suggests the most efficient way to proceed with diagnostic follow-up studies. Additionally, it shows the importance of fetal sex confirmation in all normal PGT-A studies.