MOSAICISM IS A CONDITION IN WHICH CELLS WITHIN THE SAME INDIVIDUAL HAVE A DIFFERENT GENETIC MAKEUP. THE CYTOGENETIC ABNORMALITY CONFINED TO PLACENTA, MOST OFTEN THE TRISOMY STUDIED BY CVS(CHORIONIC VILLUS SAMPLING), DURING TO 9-11 WEEKS OF GESTATION IS KNOWN AS THE CONFINED PLACENTAL MOSAICISM.