A nurse is discussing various options for prenatal testing with a client who is at 7 weeks of gestation and has a family history of chromosomal abnormalities. Which of the following information should the nurse include?

Choice A reason: The Coombs test is not used to determine cystic fibrosis. Instead, it is primarily used to detect antibodies that may cause hemolytic disease of the newborn, such as Rh incompatibility. Cystic fibrosis is diagnosed through genetic testing or sweat chloride testing, not through Coombs. Therefore, this option is scientifically inaccurate and misleading in the context of prenatal testing. Choice B reason: Serum alpha-fetoprotein (AFP) testing is a maternal blood test performed during the second trimester, typically between 15–20 weeks of gestation. Elevated AFP levels can indicate neural tube defects such as spina bifida or anencephaly, while decreased levels may suggest chromosomal abnormalities like Down syndrome. This test is a standard part of prenatal screening and provides valuable information about fetal development. It is the correct answer because it directly relates to identifying congenital abnormalities early in pregnancy. Choice C reason: Chorionic villus sampling (CVS) is indeed a test used to detect chromosomal abnormalities, but it is performed much earlier in pregnancy, usually between 10–13 weeks of gestation. It involves sampling placental tissue to analyze fetal chromosomes. Performing CVS at 34 weeks would be inappropriate and unsafe, as it is far beyond the recommended timeframe and would not provide useful diagnostic information at that stage. Thus, this option is incorrect due to the inaccurate timing stated. Choice D reason: Amniotic fluid screening, also known as amniocentesis, is performed between 15–20 weeks of gestation. It involves sampling amniotic fluid to test for chromosomal abnormalities, genetic disorders, and certain infections. While it can detect conditions such as Down syndrome, trisomy 18, and neural tube defects, it is not specifically used to identify fetal bladder anomalies. Fetal bladder anomalies are typically diagnosed through ultrasound imaging rather than amniotic fluid analysis. Therefore, this choice is incorrect because it misrepresents the purpose of amniotic fluid screening.