Answer to Question 1
4, 5
Rationale:
1. CVS carries twice the risk of spontaneous abortion as compared with amniocentesis. Both tests will diagnose genetic disorders.
2. An amniocentesis is not done until around 14 weeks' gestation, when there is enough amniotic fluid to test. A CVS is done in the first 8 weeks of pregnancy.
3. This is a true statement.
4. CVS is performed at 812 weeks' gestation, and amniocentesis is performed at 1114 weeks.
5. Both are equally diagnostic, but because CVS is performed earlier in pregnancy, and the results are usually back in about 24 hours, the greatest advantage to CVS is earlier diagnostic information.
Answer to Question 2
1
Rationale:
1. Amniocentesis results take longer to process, and must be done at a later gestational age than CVS.
2. Limb and facial or jaw anomalies are associated with CVS, but not with amniocentesis.
3. Amniocentesis will allow genetic testing. Neural tube defects are not genetic in nature; therefore, they are not detected by either amniocentesis or CVS.
4. CVS can be performed through either a transabdominal or a transvaginal approach.