What could indicate poor fetal oxygenation during monitoring?

The presence of late decelerations is a key indicator of poor fetal oxygenation during monitoring. Late decelerations refer to a decrease in the fetal heart rate (FHR) that begins after a contraction has started, with the lowest point of the deceleration occurring after the peak of the contraction. This pattern is particularly concerning because it suggests that the fetus may be experiencing uteroplacental insufficiency, which can lead to inadequate oxygen delivery. The late timing of these decelerations implies that they are a response to a potential insufficiency in blood flow or oxygen to the fetus, signaling possible distress.

In contrast, moderate variability indicates a healthy fetal heart rate response to stimuli and suggests that the fetus is not in immediate distress. FHR accelerations are also positive signs, reflecting adequate fetal oxygenation and responsiveness. A baseline heart rate of 140 bpm typically falls within the normal range for a fetal heart rate and would not be indicative of poor oxygenation on its own. Therefore, the presence of late decelerations stands out as a concerning sign that warrants further evaluation of fetal well-being.