Hyperfibrinogenemia and polycythemia with intrauterine growth retardation in fetal lambs.

Plasma concentrations of albumin and fibrinogen and arterial hematocrits were determined during the last third of gestation in growth-retarded and control fetal lambs. The mean fetal plasma albumin concentration increased slightly as term approached and was not significantly different in the two groups. The mean plasma fibrinogen concentration did not change in the control fetuses, but was significantly elevated in the growth-retarded fetuses, as was the mean arterial hematocrit. The theoretical implications of these findings relative to capillary blood flow are discussed.