Using Oxygen Consumption Rate to Quantify the Respiratory Activity of Single Blastocyst with Dissolved-Oxygen Sensing Chips

2024 Taiwan Society for Reproductive Medicine Annual Conference Prize Paper Presentation (Basic Science)

Ping-Feng Yang^*1, , En-Hui Cheng², Yi-Ping Lin², Han-Ni Tsai², TsungHsien Lee^3,4, Chun-I Lee^2,3,4, Maw-Sheng Lee^2,3,4, Pin-Chi Tang5, Huynh Thi Ngoc Tham5, Ching-Chou Wu1*
Department of Bio-Industrial Mechatronics Engineering, National Chung Hsing University.[1] Division of Infertility Clinic, Lee Women’s Hospital.[2] Institute of Medicine, Chung Shan Medical University.[3] Department of Obstetrics and Gynecology, Chung Shan Medical University Hospital.[4] Department of Animal Science, National Chung Hsing University.[5]
 

Study Question

The current uncertainty in embryo development results in a fair in vitro fertilization (IVF) pregnancy rate. Despite the use of morphological assessment of embryos, euploidy genetic testing, and expensive and time-consuming artificial intelligence imaging culture systems to aid in the evaluation of blastocyst health, which can increase the IVF pregnancy rate, these existing clinical testing methods are costly and time-consuming and fail to truly quantify the developmental status of the embryos.
Therefore, integrating non-invasive respiratory activity estimation techniques to select the optimal blastocyst for implantation is crucial for infertility patients.
 

Study Design, Size, Duration

The study aims to establish a label-free electrochemical embryonic respiration sensing chip for grading embryo status for clinic implantation criteria. After using diffusion model analysis, the chip can quantify the oxygen
consumption rate (OCR) of embryos with dissolved oxygen (DO) ultramicroelectrode array. Before a clinical trial, quality-different by morphology (n=17) or H2O2-treated (n=4) mouse blastocysts are used as models to  compare the OCR value of different blastocysts.
 

Materials, Setting, Methods

The chips were fabricated using microfabrication techniques from the Biological Micro-Analysis-System Lab, Department of Bio-Industrial Mechatronics Engineering, National Chung Hsing University [1]. The quality-different or H2O2-treated mouse embryos are used as models to compare the OCR value of different embryos from the Division of Infertility Clinic, Lee Women’s Hospital [2](IACUC no.:2727)and Department of Animal Science of National Chung Hsing University [5].

Main Results

The results show a positive correlation (Pearson r=0.71) between morphological classification and embryo OCR values. Additionally, the good-level and fair/poor-level blastocysts can significantly distinguish through an ROC curve with a 100% sensitivity when the OCR value is larger than 58.3 fmol/s.

Conclusion

This technology develops an embryo quality testing chip and a rapid quantification technique for OCR. The chip’s 3D microstructure accurately positions the blastocyst, and the solid-state salt bridge stabilizes the reference electrode’s potential. The embryo OCR measured by the chip shows a positive correlation and sensitivity with morphological classification, offering great potential for selecting high-quality embryos and enhancing the implantation rate of single embryos. Future efforts will continue with clinical measurements on human blastocysts.