Early decelerations are common; they generally indicate head compression.
This segment is the fourth in my fetal monitoring series. My goal aims to help moms and dads understand what fetal monitoring is, and why it is done during labor and delivery.
Fetal monitoring technology first surfaced in the 1970’s, so it’s been around a long time.We understand it pretty well after nearly fifty years and it often is beneficial in achieving the goal of a healthy, happy baby.
Today, I’m talking about fetal heart decelerations. Remember, normal fetal heart rates range from 110 to 160, but what does it mean when the baby’s heart rate falls below the baseline?
Decelerations come in several varieties. There are early decelerations, variable decelerations and late decelerations. There’s also prolonged late decelerations. And each category has certain important meaning.
As an example, look at the above tracing, this screenshot illustrates early decelerations. As the monitor moves from left to right in the top portion, you’ll notice how the fetal heart dips slowly down below the baseline of 140 (even below 110), then recovers, then dips slowly down and recovers again.
Now focus your attention on the bottom portion of the screenshot. Compare the dip of the fetal heart rate with the rise of the uterine contraction. As the fetal heart rate goes down, the uterus contracts sequentially upward with it. And so it goes, from left to right.
Early decelerations are usually not concerning. We know from experience they indicate head compression and believe me, that’s normal during labor and delivery – the uterus contracting to push the baby through the birth canal causes head compression – it has to, to make progress and the more intense the contraction, the more likely we see early decelerations in the fetal heart tracing.
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