Late fetal heart decelerations concern nurses, midwives and doctors alike, especially if they occur frequently and if they are “deep.” The above screenshot illustrates a classic example. In this one, the baby’s heart rate is going along and all of a sudden it drops way down into the 60 beats per minute range, then gradually turns back up and recovers.
Now draw your attention to the bottom portion of this strip. Notice how the slowing heart rate occurs after the peak of uterine contraction. It’s almost like the heart rate deceleration is sliding down the slope of the contraction.
This is a late deceleration, and if coupled with things like meconium (baby’s first poop), vaginal bleeding, poor progression of labor or the if contractions are really intense or too frequent, the baby may be or is probably distressed and re-assessment as well as intervention are in order.
Also note in this example the extreme variance/variability in the baby’s heart rate (illustrated by the jagged lines seen in upper portion). Coupled with the late deceleration, this is convincing evidence that something’s not quite right.
The full-length YouTube video on the entire fourth segment: Fetal Monitoring: Decelerations can be found at: https://www.youtube.com/watch?v=9LNkEAMof0g&t=38s