Fetal Physiology and Antepartum Fetal Surveillance

Fetal surveillance is an integral part of prenatal care, especially in the last trimester. In order to understand antepartum fetal surveillance modalities, clinicians must be familiar with fetal physiology. This chapter will describe fetal cardiac physiology, which is primarily monitored. The authors will also describe fetal respiratory physiology and neurologic function to understand the impact of fetal distress, which may result in lifelong sequelae. In the subsequent sections, antepartum fetal surveillance technology is described, including nonstress tests, the biophysical profile, and umbilical artery Doppler velocimetry. The indications and limitations of these studies will be described. The purpose of this chapter is to educate clinicians on the roles of these modalities and the assessment they offer.