this prevalence and restricted spectrum of chromosome abnormalities , which included monosomy x , triploidy , gonosomal aneuploidy , trisomies 13 , 18 , and 21 , resembled the prevalence and spectrum found among perinatal deaths and differed both in prevalence and type from those chromosome abnormalities found in spontaneous abortions occurring during the embryonic period .
C0008626
of chromosome abnormalities
C0002938
aneuploidy