Nomograms for rapid estimation of intravascular intrauterine exchange transfusion.

Fetal exchange transfusion is complicated by the fact that vascular access must be maintained while the number of exchanges needed to achieve a desired post-transfusion hematocrit is calculated. A rapid method for estimating the number of exchange transfusions would greatly simplify fetal exchange transfusion for blood group isoimmunization. In this report, we present a graphic method for determining the number of exchange transfusions necessary to achieve a post-transfusion hematocrit of 45%, using a nomogram for 5- and 10-mL exchange transfusion volumes.