What defines tachycardia in a fetal heart rate?

Tachycardia in a fetal heart rate is identified as a sustained heart rate greater than 160 beats per minute (BPM). The criterion for defining tachycardia is a fetal heart rate exceeding this threshold for a duration of 10 minutes or more. This standard aligns with clinical guidelines for assessing fetal wellbeing during monitoring.

In this context, a heart rate of 160 BPM sustained for more than 10 minutes indicates a concern that must be evaluated further, as it may suggest underlying issues such as fetal distress or maternal factors affecting the fetus. Recognizing this allows healthcare providers to respond appropriately, whether through further monitoring or interventions.

The other options either propose a higher threshold (like 170 BPM or 180 BPM) or shorter durations not consistent with the established definition of tachycardia, leading to a misunderstanding of what constitutes an elevated fetal heart rate in clinical practice. Thus, the correct identification of fetal tachycardia is critical for ensuring proper fetal health assessments and interventions.