In our study, 61% of patients had NT-proBNP values compatible with a diagnosis of HF (considering the age-related cut-off of NT-proBNP ≥ 1800 pg/ml), while a significant portion of patients (32.8%) laid in the "gray zone", with NT-proBNP values between 300 and 1799 pg/ml, that did not exclude the presence of HF and could highlight significant underlying cardiac structural and functional abnormalities. This evidence concerns the gene NPPB and hydrops fetalis.