Preimplantation genetic screening of blastocysts by multiplex qPCR followed by fresh embryo transfer: Validation and verification

Abstract

Background: Aneuploidy is an important etiology of implantation failure and quantitative real-time polymerase chain reaction (qPCR) seems a promising preimplantation genetic screening (PGS) technology to detect aneuploidies. This verification study aimed at verifying the impact on reproductive outcomes in in vitro fertilization (IVF) cycles using fresh embryo transfer (FET) in which the embryos were selected by blastocyst biopsy with qPCR-based PGS in our settings. Results: A total of 13 infertile couples with more than once failed in vitro fertilization were enrolled during July to October of 2014. PGS was conducted by qPCR with selectively amplified markers to detect common aneuploidies (chromosomes 13, 18, 21, X, and Y). The design of the qPCR molecular markers adopted the locked nucleic acid (LNA) strategy. The blastocyst biopsy was performed on Day 5/6 and the PGS was done on the same day, which enabled FET. A total of 72 blastocysts were biopsied. Successful diagnoses were established in all embryos and the rate of successful diagnosis was 100 %. The aneuploidy rate was 38.9 % (28/72). 28 embryos were transferred. The clinical pregnancy rate was 61.5 % (8/13) per cycle. Early first trimester abortion was encountered in 1 and the ongoing pregnancy rate was 53.8 % (7/13) per cycle. Conclusion: This study verified the favorable outcome of adopting PGS with qPCR + FET in our own setting. Expanding the repertoire of aneuploidies being investigated (from a limited set to all 24 chromosomes) is underway and a randomized study by comparing qPCR and other PGS technologies is warranted.