Amniotic Fluid Natriuretic Peptide Levels in Fetuses With Congenital Heart Defects or Arrhythmias

BACKGROUND: We have previously demonstrated that umbilical cord plasma natriuretic peptide (NP) levels reflect the severity of heart failure (HF) in fetuses with congenital heart defects (CHD). The aim of this study was to evaluate the significance of amniotic fluid (AF) NP levels in the assessment of HF in fetuses with CHD or arrhythmia. METHODS AND RESULTS: This was a prospective observational study at a tertiary pediatric cardiac center. A total of 95 singletons with CHD or arrhythmia, and 96 controls from 2012 to 2015 were analyzed. AF concentrations of atrial NP (ANP), B-type NP (BNP) and N-terminal pro-B-type NP (NT-proBNP) at birth were compared with ultrasonographic assessment of fetal HF using the cardiovascular profile (CVP) score. Multivariate analysis showed that a CVP score ≤5 and preterm birth are independently associated with high AF NT-proBNP levels. AF NT-proBNP levels of fetuses with CHD or arrhythmia inversely correlated with CVP score (P for trend <0.01). In contrast, AF concentrations of ANP and BNP were extremely low, and it was difficult to assess the degree of fetal HF based on them. CONCLUSIONS: AF NT-proBNP concentrations increase in stepwise fashion with the severity of HF in fetuses with CHD or arrhythmia; it was the optimal NP for assessing the fetal HF.