A client asks the nurse about the risks and complications associated with prenatal ultrasound.

Which of the following responses by the nurse is accurate?

"It is a screening test for spinal defects in the fetus."

The MSAFP test is a blood test that measures the amount of alpha-fetoprotein (AFP) in the mother’s blood.

AFP is a protein produced by the baby during pregnancy.The test helps to assess the baby’s risk of certain birth defects, such as neural tube defects, which are abnormalities in the development of the brain and spine.

A. “It is a diagnostic test for spinal defects in the fetus.” This statement is wrong because the MSAFP test is not a diagnostic test.

It only indicates the probability of having a spinal defect, but it does not confirm or rule out the condition.A diagnostic test, such as an ultrasound or amniocentesis, is needed to make a definitive diagnosis.

C. “It is a diagnostic test for chromosomal abnormalities in the fetus.” This statement is wrong because the MSAFP test is not a diagnostic test for chromosomal abnormalities either.

It only indicates the probability of having a chromosomal abnormality, such as Down syndrome, but it does not confirm or rule out the condition.A diagnostic test, such as a chorionic villus sampling (CVS) or amniocentesis, is needed to make a definitive diagnosis.

D. “It is a screening test for chromosomal abnormalities in the fetus.” This statement is partially correct, but not the best answer.

The MSAFP test alone is not very accurate for screening chromosomal abnormalities.It is usually combined with other blood tests and an ultrasound to form a more reliable screening test called a quad screen or an integrated screen.

The normal range of MSAFP levels varies depending on the gestational age of the baby and the laboratory methods used.Generally, the MSAFP levels increase until about 15 weeks of pregnancy and then decrease until delivery.The average MSAFP level at 15 weeks of pregnancy is about 38 ng/mL.However, different laboratories may have different reference ranges, so it is important to consult your healthcare provider for your specific results and interpretation.

A Doppler ultrasound blood flow analysis measures the velocity of blood flow in the uterine and fetal vessels.

This test can help assess the fetal well-being and oxygenation in cases of intrauterine growth restriction (IUGR).

Choice B is wrong because the amount of amniotic fluid in the uterine cavity is measured by ultrasound, not Doppler.

Choice C is wrong because the pressure of blood flow in the umbilical cord is not directly measured by Doppler, but rather inferred from the resistance index or pulsatility index.

Choice D is wrong because the oxygen saturation level of fetal blood is not measured by Doppler, but rather by fetal scalp sampling or pulse oximetry.