What type of FHR variability is indicated by an amplitude range less than 5 BPM?

Minimal variability in fetal heart rate (FHR) is characterized by an amplitude range of less than 5 beats per minute (BPM). This means that there is some fluctuation in the heart rate, but it is very limited. In clinical practice, minimal variability can indicate several factors, including fetal sleep cycles, maternal sedation, or potential fetal distress due to hypoxia or other conditions. Understanding FHR patterns is crucial for monitoring fetal well-being during labor and delivery, as well as for making informed clinical decisions.

The amplitude range of less than 5 BPM signifies that the FHR lacks the healthy fluctuations seen in more desirable variability, such as moderate variability (which has an amplitude of 6 to 25 BPM) or marked variability (which exceeds 25 BPM). Absence of variability, on the other hand, indicates no fluctuations at all, which can be a concerning sign. Recognizing these differences allows practitioners to assess fetal compromise and determine the need for further intervention or monitoring.