What indicates a negative CST result?

A negative contraction stress test (CST) result implies that the fetus can tolerate the stress of contractions without signs of distress, particularly the absence of late decelerations. Late decelerations typically indicate compromised fetal oxygenation, suggesting that the fetus may be negatively affected by uterine contractions.

When the baseline fetal heart rate (FHR) is normal and there are no late decelerations present during the test, it indicates that the fetal heart rate response is reassuring, reflecting adequate fetal well-being and oxygenation.

In contrast, the other options suggest potential complications or abnormal findings related to the fetus. Early decelerations, while typically not concerning, can represent head compression but do not directly imply a negative CST. Intermittent variable decelerations can be concerning depending on their characteristics (such as duration and recovery), indicating potential cord compression issues. Persistent fetal tachycardia can signal distress or hypoxia, which points to potential fetal compromise during testing. Therefore, the presence of a normal baseline FHR without late decelerations is the hallmark of a negative CST result, confirming fetal well-being under stress.