SMAD2 and hydrops fetalis: There was an overall effect of HF feeding to increase cardiac mRNA abundance of the fibrosis-related genes mitogen-activated protein kinase kinase kinase 7 (Map 3k7; P < 0.01), transforming growth factor beta 3 (Tgfb3; P < 0.01), transforming growth factor beta receptor 2 (Tgfbr2; P < 0.001), transforming growth factor beta receptor 3 (Tgfbr3; P < 0.001) and Smad2 (P < 0.001) in both nulliparous and postpartum female mice compared with LF controls (Fig. 4a).