Current knowledge suggests that parental age has many influences on offspring. This topic has been exhaustively reviewed in Finch's monograph. The major maternal age-related changes in humans are increases in fetal aneuploidy later in reproductive life; Down's syndrome (trisomy 21); Kleinfelter's syndrome (XXY); Edward's syndrome (trisomy 18); and Patau's syndrome (trisomy 13). Despite a recent dramatic decrease in fetal death rates, advanced maternal age remains an important independent risk factor for fetal death.