Final answer:
Late decelerations in FHR are concerning because they may indicate uteroplacental insufficiency and fetal hypoxia, requiring quick assessment and intervention.
Step-by-step explanation:
Among the fetal heart rate (FHR) findings listed, late decelerations would concern the nurse during labor. Late decelerations can be associated with uteroplacental insufficiency and may indicate that the fetus is experiencing hypoxia. This is in contrast to variability, which refers to fluctuations in the baseline FHR and is considered a sign of a healthy fetus; accelerations, which are temporary increases in FHR and are typically seen as reassuring; and early decelerations, which are usually associated with head compression during contractions and not typically concerning. Consistent late decelerations, however, require prompt assessment and intervention to ensure fetal wellbeing.