PENK and hydrops fetalis: We however did not observe an interaction between PENK concentrations and KDIGO risk category, nor with the presence of eGFR <60 ml/min/1.73 m2, with respect to new‐onset HF, but the numbers of subjects with a high‐risk category and/or eGFR <60 ml/min/1.73 m2 may have been too low to confidently show this interaction in these subpopulations of interest.