Final answer:
A fetal heart rate that is not less than 100 at the start and peaks at the contraction peak describes accelerations. These are a reassuring sign of fetal well-being during labor, in contrast to other patterns like decelerations.
Step-by-step explanation:
Patterns of fetal heart rate (FHR) changes during contractions can provide key insights into fetal wellbeing during labor and delivery. The description given, where the FHR is not less than 100 at the beginning of contractions and peaks at the contraction peak, describes accelerations. Accelerations are generally considered reassuring and a sign of a healthy fetal response to the natural stresses of labor. They are distinct from other FHR patterns such as early decelerations (which occur with contractions as a mirror image, due to head compression), late decelerations (which occur after the contraction has started, usually due to uteroplacental insufficiency), and variable decelerations (which can happen at any time and are typically due to cord compression).