Breakdown of chromosomal abnormalities in spontaneous abortions Trisomy 16 15% 13, 18,21 9% XXX. XXY XYY 1% All others 27% Monosomy X (45, X or XO) 18% Triploidy 7% Tetraploidy 6% Other Total 100%Trisomy XXX, XXY, XYY All others Monosomy X (45,X or XO) Triploidy Tetraploidy Other Total 15% 9% 1% 27% 18% 17% 6% 7% Breakdown of chromosomal abnormalities in spontaneous abortions: 100% 16 13, 18, 21