Which observation during labor should a nurse notify the healthcare provider?

The correct observation that a nurse should notify the healthcare provider about is related to late decelerations. This is because late decelerations are indicative of fetal distress and can signal a potential issue with placental insufficiency, which may compromise the oxygen supply to the fetus. This situation can lead to significant complications if not addressed promptly.

In contrast, early decelerations are considered a normal response to contractions, typically caused by head compression during labor, reflecting a well-oxygenated fetus. Variable decelerations can also occur due to umbilical cord compression, but their clinical significance may vary depending on the pattern and associated findings. Fetal heart rates between 170-200 beats per minute for a duration of 20 minutes may indicate tachycardia, which may warrant assessment but is not an immediate cause for alarm compared to the implications of late decelerations. Therefore, late decelerations require immediate notification of the healthcare provider to ensure the safety and well-being of both the mother and the fetus.