FZD1 and hydrops fetalis: In the K-means analysis and WGCNA, we found several DEGs, such as FZD1 [23, 24], GLI2, KRT25 [25, 26], LAMA5 [27, 28], LRP4 [29, 30], SOSTDC1 [31, 32], TGFβ2 [33, 34], TMEM79 [35], BMP7 [36, 37], WNT10A [38], ZDHHC21 [39], SOX10 [40, 41], ITGB4 [42], KRT14 [43], and ITGA6 [44], which are associated with the development of the epidermis and HF.