A nurse is performing an abdominal ultrasound for a client who is at 28 weeks of gestation.

The nurse should instruct the client to do which of the following before the procedure?

A low level of AFP (<0.5 MoM) in a pregnant woman can indicate that the fetus has a chromosomal abnormality, such as Down syndrome or Edwards syndrome.

This is because these conditions affect the development of the fetal liver, which produces AFP.

Choice A is wrong because neural tube defects, such as spina bifida, are associated with high levels of AFP (>2.5 MoM) in the maternal blood.

This is because AFP can leak from the open spinal canal of the fetus into the amniotic fluid and then into the maternal blood.

Choice C is wrong because maternal weight-related factors do not affect the level of AFP in the maternal blood.

However, they can affect the interpretation of the AFP test results, as the test needs to be adjusted for maternal weight, age, ethnicity, and gestational age.

Choice D is wrong because fetal demise (death) can also cause high levels of AFP in the maternal blood, as the AFP from the dead fetus can leak into the amniotic fluid and then into the maternal blood.

Normal ranges of AFP in pregnant women vary depending on the gestational age and the method of measurement.

Generally, normal levels of AFP are below 10 ng/ml in nonpregnant adults and below 2.5 MoM in pregnant women.

"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.