Utility of B-type natriuretic peptides in preeclampsia: a systematic review.

BACKGROUND Preeclampsia and its complications may be associated with elevated B-type natriuretic peptide levels during and after pregnancy. METHODS We conducted a systematic review to determine whether preeclampsia and/or related cardiovascular complications, eclampsia and preterm delivery are associated with elevated natriuretic peptide levels. Three bibliographic databases were searched, using the terms "natriuretic peptide", "pregnancy", "preeclampsia", "eclampsia" and "BNP". Twelve studies fulfilled our inclusion criteria for full paper analysis. The data were too heterogeneous to allow for meaningful quantitative analyses. RESULTS In healthy patients, B-type natriuretic peptide levels did not change during pregnancy. Compared with normal pregnancies, preeclamptic patients were shown to have significantly higher natriuretic peptide levels in the third trimester, which remained elevated for 3-6 months postpartum. Several papers suggested that cardiovascular dysfunction in preeclampsia is associated with NP elevation. Abnormalities were elevated systemic vascular resistance and cardiac filling pressures, decreased cardiac output, left ventricular diastolic dysfunction, and elevated left ventricular mass index. One investigation found that natriuretic peptide levels were higher in preeclamptic women who subsequently had preterm delivery, compared with those who delivered after 34 weeks. There were no data on natriuretic peptide levels in eclampsia. CONCLUSIONS Preeclampsia is associated with elevated natriuretic peptide levels. Cardiovascular complications and preterm delivery in this setting may also be associated with elevated natriuretic peptide levels. Large prospective studies of natriuretic peptide measurement in preeclampsia are needed to determine whether elevated levels predict the development of severe preeclampsia and/or associated complications.