The physician prescribes a maternal blood test for alpha fetoprotein for a nulligravid client at 16 weeks’ gestation. When developing the teaching plan, the nurse bases the explanations on the understanding that this test is used to detect which of the following?
1. Neural tube defects.
2. Chromosomal anomalies.
3. Inborn errors of metabolism.
4. Lecithin-sphingomyelin ratio.
A blood test for alpha fetoprotein is recommended at 15 to 20 weeks’ gestation to screen for neural tube defects such as spina bifida. Chorionic villi sampling is used to detect chromosomal anomalies. Amniotic fluid amino acid determination is used to detect inborn errors of metabolism such as phenylketonuria. An amniocentesis is used to determine the lecithin- sphingomyelin ratio for fetal lung maturity, indicated by a ratio of 2:1, or chromosomal abnormalities.
CN: Reduction of risk potential; CL: Apply