“…Using single biochemical markers usually has a low predictive value in the first trimester. PAPP-A, a glycoprotein synthesized in the placenta, has been shown to be a powerful predictive biochemical marker of PE when combined with Doppler ultrasound, reaching 70% sensitivity at 95% specificity (Spencer et al, 2008;Goetzinger et al, 2010;Anderson et al, 2011). However, some recent studies evaluating PAPP-A as a firsttrimester predictive marker for PE showed conflicting results that indicated no differentiation between complicated and uncomplicated pregnancies (Mikat et al, 2011;Stirnemann et al, 2011).…”