A nurse is teaching a group of nursing students about cord prolapse.

The nurse explains that cord prolapse can be classified into three types: overt, occult, and funis.

What is the difference between these types?

The correct answer is choice B. It creates more space for the cord to slip past the presenting part.Polyhydramnios is a condition where there is excessive accumulation of amniotic fluid during pregnancy.This can cause the fetus to be malpositioned or not engaged in the pelvis before labor, which increases the risk of cord prolapse.Cord prolapse is when the umbilical cord drops into the vagina ahead of the baby, which can compromise blood flow and oxygen delivery to the fetus.

Choice A is wrong because it is not the fetal movement that causes cord prolapse, but the displacement of the presenting part from the cervix.

Choice C is wrong because it is not the pressure on the membranes that causes cord prolapse, but the rupture of the membranes with a high or mobile presenting part.

Choice D is wrong because it is not the reduced cushioning effect of the amniotic fluid that causes cord prolapse, but the increased space for the cord to slip past the presenting part.

The correct answer is choice C. Umbilical cord compression.Variable decelerations are abrupt drops in the fetal heart rate below baseline that last 15 seconds to less than two minutes.They are caused by reduced blood flow and oxygen delivery to the fetus due to umbilical cord compression.The onset, depth, and duration of variable decelerations vary with uterine contractions or fetal movement.They can be periodic or episodic.

Choice A is wrong because fetal head compression causes early decelerations, which are symmetrical decreases and return-to-normal of the fetal heart rate that is linked to uterine contractions.Early decelerations are benign and do not affect fetal oxygenation.

Choice B is wrong because uteroplacental insufficiency causes late decelerations, which are gradual decreases in fetal heart rate after a uterine contraction.Late decelerations may indicate that a fetus has high levels of acid in the blood (a condition called impending fetal academia), which is often caused by a lack of oxygen.

Choice D is wrong because maternal hypotension can cause late decelerations, not variable decelerations.Maternal hypotension can reduce the blood flow to the placenta and affect fetal oxygenation.