Measurement of maternal serum PAPP-A at late in the first trimester of pregnancy in conjunction with maternal age, maternal serum Human Chorionic Gonadotropin (HCG) and fetal nuchal translucency is used to determine the risk of fetal abnormalities such as trisomy 21, with a detection rate of over 90% for a 5% false positive rate (8-11). Here, PAPPA is linked to trisomy 21.