What does a late deceleration indicate in relation to uterine contractions?

A late deceleration is characterized by a pattern where the fetal heart rate shows a decrease that begins after the peak of a uterine contraction and returns to baseline after the contraction has ended. This indicates that the deceleration occurs in relation to the uterine contraction, specifically following it. Late decelerations are often associated with uteroplacental insufficiency, where the placenta is not delivering an adequate supply of blood (and thus oxygen) to the fetus during contractions, which is why the nadir—the lowest point of the deceleration—happens after the peak of the contraction.

The correct choice reflects this relationship by indicating that the nadir follows the contraction, providing clinical insight into potential fetal distress. Understanding this association helps healthcare providers monitor fetal well-being and take appropriate action if necessary. Recognizing late decelerations can lead to interventions that aim to improve placental blood flow and oxygenation for the fetus.