Less-invasive chromosome screening of embryos and embryo assessment by genetic studies of DNA in embryo culture medium
- 40 Downloads
To perform a preliminary exploration of a new embryo rank in clinical practice by combining the embryo chromosome copy number and mitochondrial copy number analysis of DNA extracted from embryo culture medium and blastocoel fluid.
Eighty-three ICSI embryos from day 2 or day 3 were cultured to day 5 or day 6. Thirty-two blastocysts of 3 cc or above were obtained. Culture medium and blastocoel fluid were collected at 24 h before blastocyst formation. The genomic DNA and mitochondrial DNA (mtDNA) from the culture medium combined with blastocoel fluid and the whole blastocyst were amplified and sequenced by MALBAC-NGS. We compared the chromosomal information generated by the new protocol from the culture medium and the information employed by the whole embryo method. A multivariable linear regression was performed to study the impact of the blastocyst morphological score, chromosomal abnormality, embryo mtDNA copy number, and female age on the culture medium mtDNA copy number.
(1) The DNA from 31 blastocysts was successfully amplified, and the successful amplification rate was 96.9% (31/32). The success rate of the amplification of genomic DNA extracted from the culture medium was 87.5% (28/32). (2) There were 18 blastocysts in which the less invasive method and the whole embryo method revealed the same results. The consistency rate was 66.7% (18/27). (3) The culture medium mitochondrial DNA copy number (MCN) had a significantly positive correlation with the blastocyst mitochondrial DNA copy number (P = 0.001), female age (P = 0.012), and blastocyst score (P = 0.014), but there was no obvious correlation with blastocyst chromosome (P = 0.138).
The preliminary exploration result of the less invasive approach for having an embryo rank was not satisfying, which still awaits further long-term evaluation.
KeywordsMedium Genomic DNA Mitochondrial DNA MALBAC NGS Preimplantation genetic testing In vitro fertilization and embryo transfer Less-invasive
We are grateful to our patients for their sincere participation in this study and thank each author for their hard work.
X.B. designed and coordinated the study. H.X., C.Y., L.F., and X.S. collected the clinical cases. J.Z. and H.X. performed and analyzed the data. J.Z. wrote the draft of the manuscript. All authors read and approved the final manuscript.
Compliance with ethical standards
Ethical approval was obtained from the Scientific and Ethical Committee of Tianjin Medical University for the experimental protocol (IRB2017-155-01). A detailed patient consent form was signed for each embryo sample used in this study.
Conflict of interest
The authors declare that they have no conflict of interest.
- 4.Tobler KJ, Brezina PR, Benner AT, du L, Xu X, Kearns WG. Two different microarray technologies for preimplantation genetic diagnosis and screening, due to reciprocal translocation imbalances, demonstrate equivalent euploidy and clinical pregnancy rates [J]. J Assist Reprod Genet. 2014;31(7):843–50.CrossRefGoogle Scholar
- 36.Werner MD, Hong KH, Franasiak JM, Forman EJ, Reda CV, Molinaro TA, et al. Sequential versus Monophasic Media Impact Trial (SuMMIT): a paired randomized controlled trial comparing a sequential media system to a monophasic medium. Fertil Steril. 2016;105:1215–21. https://doi.org/10.1016/j.fertnstert.2016.01.005.CrossRefPubMedGoogle Scholar