A client is scheduled for a transvaginal ultrasound in two weeks.

The client asks the nurse what they should do to prepare for the test.

What is the best response by the nurse?

This finding indicates that the umbilical cord is being compressed, which can reduce the blood flow and oxygen supply to the fetus.

Variable decelerations are abrupt decreases in the fetal heart rate (FHR) that vary in shape, duration, and degree of fall below the baseline.

They are seen as W- or U-shaped waves on the monitor.

Choice B is wrong because fetal hypoxia is not indicated by variable decelerations, but by late decelerations, which are gradual decreases in the FHR that begin after the peak of the contraction and return to baseline after the contraction ends.

Late decelerations are associated with uteroplacental insufficiency, which means that the placenta is not delivering enough oxygen to the fetus.

Choice C is wrong because normal placental function is not indicated by variable decelerations, but by reassuring FHR patterns, such as moderate variability (6 to 25 beats per minute) and accelerations (increases in the FHR above the baseline).

Normal placental function ensures adequate fetal oxygenation and well-being.

Choice D is wrong because adequate fetal oxygenation is not indicated by variable decelerations, but by reassuring FHR patterns, such as moderate variability and accelerations.

Adequate fetal oxygenation means that the fetus is not experiencing hypoxia or distress.

Normal ranges for FHR are 110 to 160 beats per minute at term and 120 to 160 beats per minute before term.

Normal ranges for uterine contractions are 2 to 5 contractions in 10 minutes, lasting less than 90 seconds each.

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.