The causes of misdiagnosis and adverse outcomes in PGD

TLDR

Since 1997, the European Society of Human Reproduction and Embryology PGD Consortium has recorded 15,158 PGD cycles, revealing that misdiagnosis arises from cell confusion, wrong embryo transfer, contamination, allele dropout, probe failure, mosaicism, and that single‑cell diagnosis remains technically challenging with unavoidable risk. The study aims to prevent misdiagnosis by implementing robust diagnostic methods and quality standards in laboratories. Among 15,158 PGD cycles, 24 misdiagnoses and adverse outcomes were reported, with 12 in 2,538 PCR cycles and 12 in 12,620 FISH cycles.

Abstract

The European Society of Human Reproduction and Embryology PGD Consortium has collected data on PGD cycles and deliveries since 1997. From 15,158 cycles, 24 misdiagnoses and adverse outcomes have been reported; 12/2538 cycles after polymerase chain reaction and 12/12,620 cycles after fluorescence in situ hybridization. The causes of misdiagnosis include confusion of embryo and cell number, transfer of the wrong embryo, maternal or paternal contamination, allele dropout, use of incorrect and inappropriate probes or primers, probe or primer failure and chromosomal mosaicism. Unprotected sex has been mentioned as a cause of adverse outcome not related to technical and human errors. The majority of these causes can be prevented by using robust diagnostic methods within laboratories working to appropriate quality standards. However, diagnosis from a single cell remains a technically challenging procedure, and the risk of misdiagnosis cannot be eliminated.