Based on an analysis of two-years of maternal serum screens with data on obstetrical outcomes, the BC Prenatal Genetic Screening Program has established that the cut-offs for indicating a significant increased chance of abnormal obstetrical outcomes are PAPP-A ≤0.15MoM, uE3≤0.40MoM, AFP≥2.5MoM, hCG≥4.0MoM, and Inhibin A≥3.0MoM.
Despite the association between abnormal serum analytes and increased chance of an abnormal obstetrical outcome, these analytes do not perform well as a screening test: they have very low sensitivity and high false positive rates. As such, 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