A nurse is providing education to a client who is scheduled to undergo chorionic villus sampling (CVS).

Which statement by the client indicates an understanding of this test?

An equivocal CST indicates late decelerations of the FHR with less than 50% of contractions.

This means that the fetus may have some degree of hypoxia or distress, but not enough to warrant immediate delivery.

An equivocal CST may also result from hyperstimulation of the uterus, which can cause excessive contractions and reduce blood flow to the placenta.

Choice B is wrong because late decelerations of the FHR with at least 50% of contractions is a positive CST, which indicates a high risk of fetal death due to hypoxia and is a contraindication to labor.

Choice C is wrong because no late decelerations of the FHR during contractions is a negative CST, which indicates a good fetal wellbeing and tolerance of labor.

Choice D is wrong because variable decelerations of the FHR with or without contractions are not related to uterine activity and may indicate cord compression or other fetal problems.

Variable decelerations are not used to interpret CST results.

This is a contraindication for the Contraction Stress Test (CST) because it increases the risk of infection and umbilical cord prolapse.

A CST is a test that measures the baby’s heart rate during uterine contractions induced by oxytocin or nipple stimulation.

Choice A is wrong because gestational diabetes is not a contraindication for the CST.

It is a condition that affects how the body processes glucose during pregnancy and may cause complications such as macrosomia (large baby), hypoglycemia (low blood sugar) or preeclampsia (high blood pressure and protein in urine).

Choice B is wrong because mild preeclampsia is not a contraindication for the CST.

It is a condition that causes high blood pressure and protein in urine after 20 weeks of pregnancy and may affect the placenta, kidneys, liver or brain.

Choice C is wrong because preterm labor is a relative contraindication for the CST, not an absolute one.

It means that the test may be performed if the benefits outweigh the risks, but it should be avoided if possible because it may trigger early labor or delivery.

Preterm labor is defined as regular uterine contractions with cervical changes before 37 weeks of pregnancy.

Normal ranges for blood pressure are below 120/80 mmHg, for glucose are 70-100 mg/dL (fasting) or below 140 mg/dL (2 hours after eating), and for protein in urine are less than 300 mg/24 hours.