Which fetal heart rate pattern is considered non-reassuring and indicates distress?

• A. Early decelerations with normal variability
• B. Persistent late decelerations
• C. Accelerations with variability
• D. Sinusoidal pattern with baseline variability

Answer: (B)

Fetal heart rate patterns reflect how well the fetus is being oxygenated. When decelerations occur, the timing relative to contractions helps reveal the cause. Late decelerations begin after the peak of a contraction and take longer to recover, often extending beyond the end of the contraction. If they happen persistently, they indicate uteroplacental insufficiency and fetal hypoxia, signs that the fetus is not receiving enough oxygen and is at risk for acidosis. That’s why this pattern is considered nonreassuring and distressing: it directly points to a problem with placental blood flow and oxygen delivery.

In contrast, early decelerations correlate with contractions and are usually due to head compression—typically benign; accelerations with normal variability are reassuring and reflect a responsive, well-oxygenated fetus; and a sinusoidal pattern is ominous and can indicate severe fetal anemia or hypoxia, though it’s a different nonreassuring scenario. The persistent late deceleration pattern most clearly signals ongoing distress that requires prompt evaluation and intervention.