UN, but not HF, fetuses showed increased mRNA expression of the gut transcription factor Sox9 (p = 0.02, Figure 4A) compared to CON, and an associated decrease in the mRNA expression levels of Muc2 (p = 0.002, Figure 4B) and Cdx2 (p = 0.003, Figure 4C) compared to CON. This evidence concerns the gene SOX9 and hydrops fetalis.