TGFB1 and hydrops fetalis: We used the KEGG database to analyse the transcriptome results and identified eight enriched pathways associated with secondary HF development: the Wnt (ko04310), TGF-β (ko04350), Notch (ko04330), NF-κB (ko04064), PI3K-Akt (ko04151), P53 (ko04115), and AMPK (ko04152) and mTOR (ko04150) signalling pathways (Figure 4).