Principles of Fetal Electrocardiography

This chapter discusses the principles of fetal electrocardiography, starting with a brief history of fetal electrocardiography and its relevance in fetal monitoring. A key aspect of present-day fetal monitoring is the analysis of the fetal heart rate, which can be obtained from the fetal electrocardiogram (ECG). This chapter then discusses some of the key aspects of the electrophysiology of the fetal heart and then continues with the discussion of what challenges arise when recording the fetal ECG with non-invasive electrodes on the maternal abdomen. Finally, we will conclude the chapter with discussing some possibilities of the use of the fetal ECG beyond fetal heart rate analysis. The goal of this chapter is to discuss the main physiology of fetal ECG recordings and the assumptions based on this physiology that underlie some of the most widely used signal processing methods to extract the fetal heart rate. This chapter is not meant to provide a comprehensive overview of all possible signal processing methods and by no means claims that the best or most innovative signal processing methods for fetal ECG analysis are discussed: the discussion remains at the level of conceptual ideas with occasionally a practical example, inspired from my own experiences.