Final answer:
The FHR is considered reactive when the baby's heart rate meets certain criteria, such as the presence of two or more accelerations during the nonstress test. These accelerations indicate a healthy and responsive fetal nervous system.
Step-by-step explanation:
Fetal heart rate, or FHR, is deemed reactive in accordance with the Apgar scoring method when the baby's heart rate satisfies specific requirements. During the nonstress test, a reactive FHR is defined as the occurrence of two or more accelerations, which are usually increases in heart rate over a baseline within a 20-minute period. These accelerations show that the fetal nervous system is functional and sensitive. The FHR is deemed reactive, for instance, if it displays a baseline heart rate of 120 beats per minute and two or more accelerations occurring within the 20-minute period, each of which is at least 15 beats per minute above the baseline. This information indicates that the FHR is evaluated based on the presence of accelerations during the nonstress test to determine if it is reactive.