A nurse is educating a pregnant client about the Non-Stress Test (NST).

Which statement by the client indicates understanding of the test?

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 because a nuchal translucency ultrasound measures the amount of fluid behind the baby’s neck in the first trimester of pregnancy, which can indicate the risk of having a chromosomal condition like Down syndrome.

Some possible explanations for the other choices are:

Choice A is wrong because fetal growth and development are not directly related to the nuchal translucency measurement.

Fetal growth and development are assessed by other parameters such as crown-rump length, biparietal diameter, abdominal circumference, etc.

Choice B is wrong because blood flow in the umbilical cord is not measured by the nuchal translucency ultrasound.

Blood flow in the umbilical cord is assessed by Doppler ultrasound, which evaluates the resistance and velocity of blood flow in the umbilical artery and vein.

Choice D is wrong because structural abnormalities in the baby’s organs are not detected by the nuchal translucency ultrasound.

Structural abnormalities in the baby’s organs are diagnosed by a detailed anatomy scan, which is usually performed in the second trimester of pregnancy.

The normal range for nuchal translucency is between 1 mm and 3 mm.

A measurement above 3 mm is considered increased and may indicate a higher risk of chromosomal or genetic conditions.

However, a nuchal translucency ultrasound is a screening test and not a diagnostic test, so it does not confirm or rule out any condition.

It only provides a probability based on statistical calculations.

Therefore, further testing may be recommended if the nuchal translucency measurement is increased or if other risk factors are present.