Umbilical cord compression causes variable decelerations.
This session on fetal monitoring focuses on variable decelerations.
Turning your attention to the upper portion of screenshot above, you see the baby’s heart rate make a sudden dip and then quickly return back to the baseline and then a sudden dip and return back to the baseline. This screenshot is an excellent example of variable decelerations.
Now examine the bottom portion of the strip. That’s a record of the uterine contractions. Notice how the fetal heart decelerations occur at the same time as the uterine contractions. Simultaneous with the uterine contractions, there’s a sharp downward spike in the fetal heart.
Variable decelerations are the result of umbilical cord compression. The umbilical cord is the baby’s life line, so prolonged cord compression is problematic and can lead to fetal distress. Labor nurses usually act aggressively to modify it. Frequently, just changing the mother’s position will solve the problem, sometimes we have to do more, which I will discuss more thoroughly in the fifth and the final segment of this series on fetal monitoring.
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