Some types of FHR decelerations are common during labor. Others suggest fetal stress and demand further evaluation or intervention. Sometimes the FHR not only dips down, it stays down and does not return to its usual level. This is an ominous situation that demands immediate delivery. FHR decelerations or bradycardia episodes come in three types.
Early decelerations are normal and common.
These decelerations are called early because they occur early during a uterine contraction . The FHR rarely goes below 100 beats per minute. The cause of these decelerations is head compression during uterine contractions. Late decelerations cause more concern. They are called late because they first appear at or after the peak of the uterine contraction.