In contraction stress testing, an equivocal result is characterized by what?

In contraction stress testing, an equivocal result is characterized by what?

• A. Decelerations with UC > 2 minutes or lasting > 90 seconds
• B. No decelerations
• C. Early decelerations
• D. Late decelerations with greater than 50% contractions

Answer: (A)

Equivocal results in a contraction stress test arise when the fetal heart rate tracing shows decelerations that don’t fit clearly into the reassuring (negative) or clearly nonreassuring (positive) patterns. The key clue is that the decelerations are prolonged—lasting more than 90 seconds or extending beyond about 2 minutes. This duration is longer than typical, and while it signals potential fetal stress, it isn’t consistently present across enough contractions to confirm a nonreassuring pattern. Because of that ambiguity, the result is considered equivocal, and further evaluation is needed (such as repeating the CST or pursuing another test like a biophysical profile). For context, no decelerations with contractions would be a negative test, early decelerations are generally benign and due to head compression, and late decelerations occurring with more than half of contractions would be considered positive, indicating uteroplacental insufficiency.

Equivocal results in a contraction stress test arise when the fetal heart rate tracing shows decelerations that don’t fit clearly into the reassuring (negative) or clearly nonreassuring (positive) patterns. The key clue is that the decelerations are prolonged—lasting more than 90 seconds or extending beyond about 2 minutes. This duration is longer than typical, and while it signals potential fetal stress, it isn’t consistently present across enough contractions to confirm a nonreassuring pattern. Because of that ambiguity, the result is considered equivocal, and further evaluation is needed (such as repeating the CST or pursuing another test like a biophysical profile).

For context, no decelerations with contractions would be a negative test, early decelerations are generally benign and due to head compression, and late decelerations occurring with more than half of contractions would be considered positive, indicating uteroplacental insufficiency.