Sensors for Fetal Hypoxia and Metabolic Acidosis: A Review

Abstract

This article reviews existing clinical practices and sensor research undertaken to monitor fetal well-being during labour. Current clinical practices that include fetal heart rate monitoring and fetal scalp blood sampling are shown to be either inadequate or time-consuming. Monitoring of lactate in blood is identified as a potential alternative for intrapartum fetal monitoring due to its ability to distinguish between different types of acidosis. A literature review from a medical and technical perspective is presented to identify the current advancements in the field of lactate sensors for this application. It is concluded that a less invasive and a more continuous monitoring device is required to fulfill the clinical needs of intrapartum fetal monitoring. Potential specifications for such a system are also presented in this paper.

Umbilical cord lactate compared with pH as predictors of intrapartum asphyxia

“…As technology progresses, probably more and more sensors and intelligent textiles will be developed, that will be able to detect fetal hypoxia and distress before severe lesions occur. Yet, until that time, evaluating cord blood gases remains one of the most reliable ways of detecting but also excluding fetal hypoxia (20,28,29). Moreover, in today's era of defensive medicine and prenatal diagnostics, it is important to rule out IA as a contributing cause for the poor neurological outcome of neonates diagnosed prenatally with complex malformations such as holoprosencephaly, Galen vein aneurism or other brain anomalies (30)(31)(32)(33)(34)(35).…”

Relationship Between Deceleration Morphology and Phase Rectified Signal Averaging-Based Parameters During Labor

“…On the other hand, we found that the lactate correlated only with the morphological parameters in the hypoxic fetuses. A possible explanation could be due to the fact that the lactate represents the end product of anaerobic glucose metabolism, reflecting, thus, the metabolic acidosis ( 23 ). Indeed, it has been suggested that lactate concentrations, on fetal scalp and umbilical artery at birth, might be a better predictor of poor neonatal outcome than pH ( 24 ) and even if its use has not been universally adopted, lactate monitoring is recommended in several national and international guidelines ( 23 ).…”

A new microdialysis probe for continuous lactate measurement during fetal monitoring: Proof of concept in an animal model

“…Accuracy and stability of the sensor can be affected by bio-fouling, which can be caused by protein absorption, cellular adhesion, thrombus formation, and more. 23 The microdialysis technique we used adheres to these qualifications.…”