Inpatient Obstetric Nurse (NCC) Practice Exam 2025 - Free NCC Practice Questions and Study Guide

A nonreactive non-stress test (NST) in a preterm fetus is characterized by the absence of accelerations that meet the defined criteria over a specified time period. The criteria for a reassuring or reactive NST involve the presence of at least two accelerations of the fetal heart rate, with each acceleration reaching at least 15 beats per minute (bpm) above the baseline and lasting a minimum of 15 seconds, within a 20-minute window.

In the case of a nonreactive NST, specifically when considering a time frame of 90 minutes, there are no accelerations that meet this 10x10 criterion. Thus, if no accelerations are detected within this extensive monitoring period, it confirms a nonreactive status. This means that the fetal heart rate does not respond adequately, which may raise concerns regarding fetal well-being and prompts further assessment or intervention.

The other options focus on different time frames or conditions (such as decelerations), which do not define nonreactivity in the same way that the absence of accelerations does. Understanding these distinctions is crucial in interpreting fetal monitoring results effectively for the safety and health of both the mother and the fetus.