AGO1 and hydrops fetalis: To assess whether the combination of the 4 miRNAs identified in Ago1 complexes provides better distinction between HF patients and healthy individuals, compared with each individual miR, we combined relative expression levels of miR‐222‐3p, miR‐497‐5p, miR‐21‐5p and let‐7a‐5p into a single “Ago1‐HF score”.