First Trimester PAPP-A Levels Associated with Early Prediction of Pregnancy Induced Hypertension

Objective: Previous studies have suggested an association between low levels of first trimester serum Pregnancy Associated Plasma Protein-A (PAPP-A) and the occurrence of hypertension in pregnancy (PIH). The purpose of this study was to determine the predictive value of maternal PAPP-A levels in the identification of women at risk of PIH. Methods: Maternal serum PAPP-A was measured between 11-13 + 6 wks' gestation, as part of the first trimester screening of aneuploidies. Our study included only singleton pregnancies (973 cases) over a three years period. PAPP-A levels were expressed as gestational age-specific multiples of the median (MoM). Hypertension in pregnancy was documented by standard criteria. Results: One hundred and eleven pregnant women developed hypertension (8.9%). In these patients, PAPP-A levels ranged from 0.53 to 1.08 MoM. After performing a backward stepwise regression equation and a ROC curve procedure, a PAPP-A MoM value < 0.8 was able to significantly predict PIH (p < 0.001, area under the ROC curve 83%, sensitivity 68%, specificity 86%, 95 CI 0.57-0.94). Conclusion: Low levels of serum PAPP-A (?0.8 MoM) may be a potential resource in order to early screen pregnant women at increased risk of hypertension in pregnancy.