Miniaturized Electrochemical Sensors to Monitor Fetal Hypoxia and Acidosis in a Pregnant Sheep Model

Perinatal asphyxia is a major cause of severe brain damage and death. For its prenatal identification, Doppler ultrasound has been used as a surrogate marker of fetal hypoxia. However, Doppler evaluation cannot be performed continuously. We have evaluated the performance of a miniaturized multiparametric sensor aiming to evaluate tissular oxygen and pH changes continuously in an umbilical cord occlusion (UCO) sheep model. The electrochemical sensors were inserted in fetal hindlimb skeletal muscle and electrochemical signals were recorded. Fetal hemodynamic changes and metabolic status were also monitored during the experiment. Additionally, histological assessment of the tissue surrounding the sensors was performed. Both electrochemical sensors detected the pO2 and pH changes induced by the UCO and these changes were correlated with hemodynamic parameters as well as with pH and oxygen content in the blood. Finally, histological assessment revealed no signs of alteration on the same day of insertion. This study provides the first evidence showing the application of miniaturized multiparametric electrochemical sensors detecting changes in oxygen and pH in skeletal muscular tissue in a fetal sheep model.

This research was funded by CELLEX FOUNDATION. This work was financially supported by The Cellex Foundation and the Agència de Gestió d’Ajuts Universitaris i de Recerca (Grant 2017 SGR 1531). Additionally, E.E. has received support from the Departament de Salut (Grant SLT008/18/00156). The Nanobioengineering group at the Institute of Bioengineering of Catalonia (IBEC) has received support from the Commission for Universities and Research of the Department of Innovation, Universities, and Enterprise of the Generalitat de Catalunya (No. 2017 SGR 1079) and is part of the CERCA Programme / Generalitat de Catalunya and is supported by the Severo Ochoa programme of the Spanish Ministry of Science and Competitiveness (Grant SEV-2014-0425 (2015–2019)). CIBER-BBN is an initiative funded by the VI National R&D&i Plan 2008–2011, Iniciativa Ingenio 2010, Consolider Program, CIBER Actions and financed by the Instituto de Salud Carlos III with assistance from the European Regional Development Fund. L.R. would also like to acknowledge her support within the BEST Postdoctoral Programme, funded by the European Commission under Horizon 2020’s Marie Skłodowska-Curie Actions COFUND scheme (Grant Agreement No. 712754).