HIF1A and hydrops fetalis: Additionally, a significant group effect was observed (F3,92 = 8.22; P < 0.001), with HF‐SED and HF‐Ex having greater HIF‐1α mRNA expression than LF‐SED (P < 0.01 and P < 0.01, respectively) and LF‐Ex (P < 0.01 and P < 0.05, respectively).