FGF21 and hydrops fetalis: Significant or nearly significant correlations were found in the HF/n-3 group between the mRNA levels of PPARα, GPR120 or FGF21 and UCP1, whereas for the HF group, a significant positive correlation was observed between the mRNA levels of FGF21 and UCP1, however, also negative correlations were found between the mRNA levels of TLE3 and UCP1 (Additional file 1: Table S5).