A nurse is caring for a client who had chorionic villus sampling (CVS) performed at 12 weeks’ gestation and asks when she can expect results from this test.

The nurse should inform her that results are typically available within which timeframe?

This test can detect genetic disorders.

Chorionic villus sampling (CVS) is a prenatal test that involves taking a sample of tissue from the placenta to test for chromosomal abnormalities and certain other genetic problems.

The placenta is a structure in the uterus that provides blood and nutrients from the mother to the fetus.

Choice A is wrong because CVS does not provide information on neural tube defects, such as spina bifida.

For this reason, women who undergo CVS also need a follow-up blood test between 16 to 18 weeks of their pregnancy to screen for neural tube defects.

Choice C is wrong because CVS can detect chromosomal abnormalities, but not all chromosomal abnormalities are genetic disorders.

For example, Down syndrome is a chromosomal abnormality that occurs randomly and is not inherited from the parents.

Choice D is wrong because CVS cannot detect Rh sensitization, which is a condition where the mother’s immune system produces antibodies against the fetus’s blood cells.

Rh sensitization can be detected by a blood test that measures the level of antibodies in the mother’s blood.

This is because AFP levels vary according to the gestational age of the fetus, and reporting them as multiples of the median (MoM) allows for a standardized comparison.

Choice B is wrong because AFP results do not differentiate between neural tube defects and chromosomal abnormalities.

They only indicate an increased risk for these conditions, which need further testing to confirm.

Choice C is wrong because AFP results do not assess the risk of fetal demise or multiple gestation.

They only measure the amount of AFP in the maternal blood, which can be affected by various factors such as maternal weight, race, diabetes, and fetal anomalies.

Choice D is wrong because AFP results are reported as MoM regardless of factors such as maternal weight and race.

These factors are taken into account when calculating the MoM value, which adjusts for the expected variation in AFP levels among different populations.

Normal ranges for AFP MoM vary depending on the laboratory and the method used, but generally they are between 0.5 and 2.52.

Values above or below this range may indicate an increased risk for certain fetal conditions or complications.