regression-smoothed maternal age-specific rates of six different categories of cytogenetic abnormalities in recent large-scale prenatal cytogenetic studies were multiplied by independently derived fetal selection coefficients -- factors that adjust for the excess likelihood of spontaneous loss of cytogenetically abnormal fetuses -- to obtain estimated maternal age-specific rates of these categories of cytogenetic abnormalities in live-born infants .
C2916832
age
C0021270
infants