Compared with amniocentesis, chorionic villus sampling: a. Has ...

[audragclark]

Compared with amniocentesis, chorionic villus sampling:
 
  a. Has a lower risk of abortion
  b. Can be done earlier in pregnancy
  c. Is noninvasive and less painful
  d. Reveals alpha-fetoprotein level

Question 2

A diagnostic test of the amniotic fluid to determine whether the fetus is likely to develop respiratory distress is:
 
  a. Lecithin/sphingomyelin ratio (L/S ratio)
  b. Alpha-fetoprotein (AFP)
  c. Rh isoimmunization
  d. Triple marker screen

[stanleka1]

Answer to Question 1

ANS: B
Chorionic villus sampling can be done earlier than amniocentesis. It carries a higher (not lower) risk of abortion. Amniocentesis allows the measurement of alpha-fetoprotein, whereas chorionic villus sampling does not. Both procedures are invasive.

Answer to Question 2

ANS: A
The L/S ratio indicates fetal lung maturity, which helps determine whether the fetus is likely to have respiratory distress at birth. AFP levels are used to help identify possible congenital or genetic defects. Tests for Rh isoimmunization may be done if the mother is Rh negative and the fetus is Rh positive. Triple marker screening may be done with the AFP test to identify chromosomal abnormalities.