Trisomy 21 prior risk:Likelihood:Pt:^Fetus:Qn:Based on maternal age
trisomy 21 prior risk:likelihood:pt:^fetus:qn:based on maternal age
Trisomy 21 prior risk:Likelihood:Pt:^Fetus:Qn:Based on maternal age
trisomy 21 prior risk:likelihood:pt:^fetus:qn:based on maternal age