Which fetal heart rate pattern is associated with fetal distress due to uteroplacental insufficiency?

Which fetal heart rate pattern is associated with fetal distress due to uteroplacental insufficiency?

• A. Early decelerations
• B. Late decelerations
• C. Accelerations
• D. No decelerations

Answer: (B)

Uteroplacental insufficiency reduces the placenta’s ability to deliver oxygen to the fetus, especially during contractions when blood flow is further limited. The pattern that signals this distress starts after a contraction begins and does not recover until after the contraction ends—the fetal heart rate declines, reaches its lowest point after the contraction peak, and then returns to baseline. This timing reflects fetal hypoxemia and potential acidosis from insufficient placental oxygen transfer. Other patterns have different implications. Early decelerations are caused by head compression and mirror contractions; they’re generally benign and not a sign of hypoxia. Accelerations are reassuring, representing fetal movement and sufficient oxygen. No decelerations can occur in a reassuring pattern or in other non-distress scenarios, but it doesn’t specifically indicate uteroplacental insufficiency.

Uteroplacental insufficiency reduces the placenta’s ability to deliver oxygen to the fetus, especially during contractions when blood flow is further limited. The pattern that signals this distress starts after a contraction begins and does not recover until after the contraction ends—the fetal heart rate declines, reaches its lowest point after the contraction peak, and then returns to baseline. This timing reflects fetal hypoxemia and potential acidosis from insufficient placental oxygen transfer.

Other patterns have different implications. Early decelerations are caused by head compression and mirror contractions; they’re generally benign and not a sign of hypoxia. Accelerations are reassuring, representing fetal movement and sufficient oxygen. No decelerations can occur in a reassuring pattern or in other non-distress scenarios, but it doesn’t specifically indicate uteroplacental insufficiency.