The thresholds of serum NT-proBNP levels for the diagnosis of HF are age-dependent, and have been proposed as follows: (1) >1.8 ng/mL for age >75 years, (2) >0.9 ng/mL for age 50–75 years, and (3) <0.45 ng/mL for age <50 years [10]. Here, NPPB is linked to hydrops fetalis.