Variability (labor and delivery)

The normal fetal heart rate baseline is from 120 to 160 BPM and has both short and long-term “variability.” Short-Term variability means that from one moment to the next, the fetal heart speeds up slightly and then slows down slightly, usually with a range of 3-5 BPM from the baseline.  Long-Term Variability represents broad-based swings in fetal heart rate, or “waviness,” occurring up to several times a minute. One form of long-term variability of particular significance is fetal heart “acceleration.”