First-trimester maternal dried blood Down syndrome screening marker levels in early pregnancy loss

Abstract

To determine the association of free beta hCG and PAPP-A measured during first-trimester Down syndrome risk assessment with early pregnancy loss when blood is drawn prior to scheduled ultrasound. Maternal dried blood samples were collected prior to the ultrasound exam for Down syndrome risk assessment. Free beta hCG and PAPP-A levels in 55 patients who experienced loss of pregnancy prior to their scheduled ultrasound appointment were compared to 6464 control pregnancies using logistic regression. Low levels of free beta hCG and PAPP-A were associated with increased risk of early pregnancy loss. The detection rate of early pregnancy loss for a fixed 5% false-positive rate using free beta alone, PAPP-A alone and a combination of the two were 47, 36 and 49%, respectively. Free beta hCG and PAPP-A can identify pregnancies at increased risk for early pregnancy loss. More studies are needed to determine whether further evaluation of these pregnancies prior to the scheduled ultrasound is warranted.