Prenatal diagnosis at 16 weeks of pregnancy can be performed using all of the following, except:
All options given in the question are correct as all of them are used for prenatal diangosis.
But, read the question very carefully. It specifically says at “16 weeks of pregnancy”.
Cordocentesis in is done at 18–20 weeks therefore we cannot include fetal blood in this answer.
Amniotic fluid
Maternal blood
Chorionic villi
Fetal blood