In contraction stress testing, what defines a negative result?

In contraction stress testing, what defines a negative result?

• A. Late decelerations with greater than 50% of contractions
• B. No late or variable decelerations
• C. Decelerations with contractions lasting more than 2 minutes
• D. Early decelerations only

Answer: (B)

Contraction stress testing evaluates how well the fetus tolerates the stress of uterine contractions by watching heart rate changes during contractions. A reassuring (negative) result means the fetus handles contractions without signs of distress. The defining sign is the absence of late decelerations and any significant variable decelerations in response to contractions. Late decelerations point to uteroplacental insufficiency and potential fetal hypoxia when stressed, so their absence suggests adequate placental support during labor. Variable decelerations reflect cord compression; if they aren’t repetitive or severe enough to indicate distress in conjunction with contractions, the test remains reassuring. Early decelerations, caused by head compression, are usually benign and do not by themselves negate a negative result. So, the scenario described as no late or variable decelerations best fits a negative contraction stress test.

Contraction stress testing evaluates how well the fetus tolerates the stress of uterine contractions by watching heart rate changes during contractions. A reassuring (negative) result means the fetus handles contractions without signs of distress. The defining sign is the absence of late decelerations and any significant variable decelerations in response to contractions. Late decelerations point to uteroplacental insufficiency and potential fetal hypoxia when stressed, so their absence suggests adequate placental support during labor. Variable decelerations reflect cord compression; if they aren’t repetitive or severe enough to indicate distress in conjunction with contractions, the test remains reassuring. Early decelerations, caused by head compression, are usually benign and do not by themselves negate a negative result. So, the scenario described as no late or variable decelerations best fits a negative contraction stress test.