N-terminal pro-brain natriuretic peptide as a biomarker for hypertensive disorders of pregnancy

We tested the hypothesis that the cardiac biomarker N-terminal pro-brain natriuretic peptide would be elevated in hypertensive disorders of pregnancy, with an increase in levels of this biomarker across increasing gradations of disease severity. We performed a case-controlled study of women admitted to labor and delivery at the Hospital of the University of Pennsylvania between 24 and 42 weeks of gestation. Cases had hypertension that developed after 20 weeks of gestation, and controls were normotensive women presenting for delivery. N-terminal pro-brain natriuretic peptide levels were compared between cases (n=83) and controls (n=290). Cases were subclassified into gestational hypertension (n=20) and mild (n=15) and severe preeclampsia (n=48), and N-terminal pro-brain natriuretic peptide levels were compared between these subgroups. N-terminal pro-brain natriuretic peptide levels were higher in cases than in controls (81 pg/mL versus 37 pg/mL, p<0.001), with a graded increase in levels from gestational hypertension (64 pg/mL) to preeclampsia (89 pg/mL) to severe preeclampsia (157 pg/mL; p<0.001). Each log increase in N-terminal pro-brain natriuretic peptide doubled the risk of preeclampsia (odds ratio=2.10 p<0.001). N-terminal pro-brain natriuretic peptide levels were increased in hypertensive disorders of pregnancy and discriminate between subcategories of disease.