The test having the fastest lab processing time for karyo type assessment is

Amniocentesis, cordocentesis, cystic hygroma aspiration, and chorionic villus samplingare techniques of obtaining fetal tissues that are amenable to cytogenetic analysis. Amniotic fluid cellsrequire tissue culture to obtain adequate cell numbers for analysis. Chorionic villi can be harvested directlyfor extremely rapid diagnosis or can be cultured for higher banding (increased detail).