Circulating biomarkers reflecting collagen metabolism have been shown to be associated with histologically proven myocardial fibrosis in HF (carboxy‐terminal propeptide of procollagen type I, amino‐terminal propeptide of procollagen type III, and collagen type I telopeptide‐to‐serum matrix metalloproteinase‐1 ratio).21 Here, COL1A2 is linked to hydrops fetalis.