Amniocentesis to detect chromosomal abnormalities can be done as early as
Amniocentesis: examination of a sample of amniotic fluid makes possible the prenatal diagnosis of chromosomal anomalies and certain metabolic defects; the procedure can be used as early as 14th week of pregnancy when abortion of affected fetus is still feasible.
14th week of gestation
18th week of gestation
22nd week of gestation
26th week of gestation