Tacrolimus venous umbilical cord blood : maternal blood, venous umbilical cord plasma : maternal plasma and venous umbilical cord unbound : maternal unbound concentration ratios in eight patients, shown by the time after last dose of tacrolimus to blood sampling. For each ratio, the different data points represent an observation in a different subject. •, venous cord blood : maternal blood (n = 7); ▵, venous cord plasma : maternal plasma (n = 6); , venous cord unbound : maternal unbound (n = 5)