Prenatal diagnosis of Down Syndrome is by

Prenatal diagnosis of Down Syndrome is
by -
a) Karyo typing
b) Triple test
c) Fetal ultrasonography
d) All of above
Correct Answer - D
Answer- D. All of above
Following methods are used :

  1. Triple test : It includes (i) Unconjugated estrogen (estriol) :
    decreased; (ii) Maternal serum alpha-feto protein (MSAFP):
    decreased; and (iii) hCG : increased (Note : All these three markers
    are decreased in Edward syndrome)
  2. New markers : These are (i) Increased inhibin A in maternal blood;
    and (ii) Decreased PAPA (pregnancy associated plasma protein).
  3. USG : It shows : (i) Increased nuchal translucency (increased nuchal
    fold thickness) in first trimester; (ii) Ductus venous flow reversed;
    and (iii) Nasal bone hypoplasia.
  4. Karyotyping : It can be done by chorionic villus sampling at 10-12
    weeks or aminocentesis at 16-18 weeks.