Maternal Tmprss6 silencing reduces placental and fetal iron stores and impairs embryonic growth. (A) Placental tissue nonheme iron (1 placenta per litter was tested; micromoles per gram dry weight). (B) Fetal liver nonheme iron (1 fetus per litter was tested; micromoles per gram dry weight). (C) Embryo weights (all embryos across all litters); this comparison remains significant when analyzed nested by mother (t test; P < .05). Data points depict 1 placenta or embryo per point, and capped bars denote mean ± standard deviation. Statistical differences between groups were tested by unpaired t test and are represented as follows: ∗P < .05; ∗∗P < .01; ∗∗∗P < .001; ∗∗∗∗P < .0001. ns, not significant; RNAi, RNA interference.