A 28-year-old primigravida in active labor shows recurrent decelerations on CTG that vary in shape, timing, and amplitude, unrelated to uterine contractions. What is the most likely cause?

Correct option is B

Variable decelerations are abrupt, variable in shape, and commonly due to cord compression → transient obstruction of blood flow → fetal hypoxia.
Explanation of options: (a) ✘ Placental insufficiency causes late decelerations, not variable ones. (b) ✔ Correct; cord compression → variable decelerations, classic association. (c) ✘ Head compression causes early decelerations, mirroring contractions. (d) ✘ Maternal hypotension contributes to late decelerations, not variable.