A possible explanation for these findings was suggested by Arcopinto et al. [64], who stated that during the gradual development of HF the IGF-I values are normal or slightly elevated in the beginning; in the intermediate stage, IGF-I levels tend to decrease or remain unaltered; and in advanced stages, IGF-I reduces and a markedly increase in GH circulating levels occur. Here, IGF1 is linked to hydrops fetalis.