Fetal calcium content in WT and P0 fetuses at E17 and E19. Each symbol corresponds to fetal calcium content (measured as mmol per gram of ash weight) expressed as a ratio of P0/WT within a single litter. Solid line denotes median values for all of the litters shown at each gestational age. Dotted line represents ratio of 1 (no difference between P0 and WT). Absolute values expressed as mmol/g ash weight (median, interquartile range) are as follows: E17 WT (1.51, 1.35–2.14), E17 P0 (1.39, 1.18–1.75), E19 WT (4.02, 3.90–4.44), and E19 P0 (4.01, 3.26–4.30). **, P < 0.01, Wilcoxon signed-rank test.