Assessment of fetal well-being: Fetal heart rate monitoring and the fetal biophysical profile

Abstract

The primary objective of antepartum fetal surveillance is the prevention of stillbirth. Antepartum fetal surveillance, for the most part, became possible only in the second half of the 20th century, mainly due to the advent of ultrasound and external continuous electronic fetal heart rate (FHR) monitoring (EFM). Until late in the 20th century, the main methods of antepartum fetal monitoring were the measurement of fundal height and maternal kick counts. The oxytocin challenge test (OCT) was considered positive if greater than 50% of contractions were followed by late decelerations, and negative if there were no late or significant variable decelerations. A rapidly occurring acceleration following the stimulation is considered a positive response. The converse, however, is not necessarily true; the absence of a single fetal biophysical activity is not always due to hypoxia and acidosis. The biophysical activities appear progressively in normal fetuses as gestation advances.