ACE and hydrops fetalis: It could also be criticized that our comparators were enalapril and valsartan, only one within the pharmacological class of ACE inhibitors and ARB; however, this issue does not seem relevant considering that several studies have demonstrated a class effect of ACE inhibitors and ARB when used to treat heart failure with reduced ejection fraction, and enalapril was the ACE inhibitor used in the PARADIGM-HF [3].