In fetal heart rate monitoring, an acceleration most commonly indicates what?

• A. Usually means a pH is greater than 7.19
• B. Indicates fetal acidemia
• C. Predicts poor placental perfusion
• D. Indicates uterus is not contracting

Answer: (A)

Accelerations are reassuring signs of fetal well‑being. They are brief increases in the fetal heart rate that occur with fetal movement or stimulation and reflect an intact autonomic response and adequate oxygenation. When the fetus is well oxygenated, the fetal arterial pH tends to be above the threshold used to define acidemia (around 7.20), so an acceleration most commonly indicates a pH greater than about 7.19. This is in contrast to acidemic states or distress, which are not characterized by accelerations. Accelerations don’t indicate a lack of uterine contractions, and they don’t signal poor placental perfusion; those patterns would present with different fetal heart rate patterns such as decelerations or reduced variability.