Inpatient Obstetric Nurse Practice Exam 2025 – Complete Prep Guide

A reactive non-stress test (NST) for a preterm fetus is defined as having two or more accelerations of at least 10 beats per minute (bpm) from the baseline heart rate within a specified monitoring period. This definition recognizes that preterm fetuses typically have a slightly different heart rate response compared to those who are more mature.

In this context, the criteria for determining reactivity for preterm fetuses are tailored to accommodate their physiological state. The elevation of 10 bpm is indicative of an active and oxygenated fetal state, showing that the fetus is not in distress. Continuous monitoring and recognizing the significance of these accelerations are vital for the health and management of the pregnancy, especially when considering interventions or evaluating fetal well-being.

The other options present criteria that are either too high or focused on longer durations that do not apply to the preterm population, which makes them not suitable for determining reactivity in this specific scenario. Understanding the threshold of 10 bpm and the requirement for multiple accelerations is crucial for interpreting NST results effectively and ensuring appropriate clinical decisions.