MPO and hydrops fetalis: Strong considerable correlations worth emphasizing in the group of HF patients with NS are: positive correlations between FR and TPC, TP and dityrosine, and between SA and AA, GSH, DPPH, dityrosine, kynurenine, N-formylkynurenine, MPO, peroxynitrite, S-nitrosothiols, and nitrotyrosine.