Maternal serum analyte marker cut-offs have been chosen to better identify those women who are at increased risk for obstetrical complications.
The BC Prenatal Genetic Screening Program completed a two-year analysis of maternal serum screens to determine the predictive value of the serum markers for obstetrical risk. Based on our data, the cut-offs for PAPP-A and hCG have been revised to increase the predictive value of these two analytes and decrease the number of false positives. Cut-offs for AFP, uE3, and Inhibin A remain unchanged. The cut-offs are now set at PAPP-A ≤0.15MoM, uE3≤0.40MoM, AFP≥2.5MoM, hCG≥4.0MoM, and Inhibin A≥3.0MoM.
Despite this change, prenatal genetic screening (IPS/SIPS/Quad) is not indicated, and should not be ordered solely for predicting adverse obstetrical outcomes. However, for women who have had screening for Down syndrome and are found to have an abnormal serum analyte, an increased obstetrical risk does apply. See Recommended Management. Revised Dec 2020
For a referral to the EMMA* Clinic at BC Women's Hospital, visit the Maternal Fetal Medicine department website.
*Evaluating Maternal and Fetal Markers of Adverse Placental Outcomes