Final answer:
Variable decelerations in obstetrics are characterized by V or W-shaped patterns, while early and late decelerations have different patterns.
Step-by-step explanation:
Variable decelerations in obstetrics, which refer to changes in the fetal heart rate, are characterized by a V or W-shaped pattern.
These decelerations usually occur due to cord compression or head compression during contractions. On the other hand, early and late decelerations are two other types of fetal heart rate patterns that occur during labor. Early decelerations are usually associated with head compression, and they have a mirror-image appearance to the contractions. Late decelerations, on the other hand, occur due to inadequate blood flow to the placenta, and they have a delayed onset and recovery in relation to the contractions.