PAPPA and preeclampsia: in another study by Spencer et al. [9], considering the specificity of 80.0%, PP13 has a sensitivity of 50% in diagnosis of early preeclampsia and 44% in diagnosis of all cases of preeclampsia, but in this study adding PAPP-A to PP13 did not improve its sensitivity and specificity and did not have any effect in better diagnosis of preeclampsia.