Late decelerations on fetal monitoring are most associated with which condition?

• A. Placental insufficiency
• B. Umbilical cord prolapse
• C. Fetal anemia
• D. Hypertonic uterus

Answer: (A)

Late decelerations indicate fetal hypoxia due to reduced placental blood flow during labor. They start after the peak of a contraction and return to baseline after the contraction ends, showing the fetus isn’t tolerating the ongoing labor well. This pattern is most closely linked to placental (uteroplacental) insufficiency, where the placenta can’t deliver adequate oxygen to the fetus during contractions. Conditions that contribute include maternal hypertension, diabetes, post-term pregnancy, placental abruption, or impaired placental perfusion over time.

Understanding the other possibilities helps reinforce the concept. If the cord is prolapsed, decelerations are typically variable and related to cord compression rather than occurring specifically after the contraction peak. Fetal anemia may present with other signs such as tachycardia or reduced variability rather than late decelerations. Hypertonic uterus (tachysystole) can worsen placental perfusion and contribute to late decels, but the classic association remains placental insufficiency.