A 27-year-old woman is in active labor at 39 weeks’ gestation. She reports regular contractions every 3 minutes, and her cervix is 6 cm dilated with intact membranes. Continuous electronic fetal monitoring shows a baseline fetal heart rate of 140/min with moderate variability. The tocograph demonstrates contractions followed by gradual, mirror-image decreases in the fetal heart rate that return to baseline after the contraction ends.
Which of the following is the most likely explanation for this fetal heart rate pattern?
A) Fetal hypoxia
B) Fetal sleep state
C) Head compression
D) Maternal fever
E) Umbilical cord compression
