Maternal-fetal glucose gradient in normal pregnancies and in pregnancies complicated by alloimmunization and fetal growth retardation

Adequate fetal growth requires the transfer of nutrients and oxygen from the mother to the fetus. When this is compromised, abnormal fetal growth can result. Glucose, a simple sugar, is transferred from the mother to the fetus through the placenta. Various investigators have reported contrasting results regarding the amounts of glucose concentrations found throughout pregnancy. Glucose concentrations during pregnancy were measured in 25 normal pregnancies, 13 pregnancies complicated by blood incompatibilities, and 16 showing abnormal fetal growth patterns. Although the glucose measurements in the mother were similar and adequate in all the groups, the concentrations in the fetuses differed. The growth-retarded fetuses had lower glucose concentrations and less circulating oxygen than those of normal pregnancies. The group having blood incompatibility had higher glucose concentrations. It is suggested that there is a relationship between the concentrations of glucose, oxygen-carrying capacity of the blood and growth retardation. How these altered concentrations affect fetal growth requires further investigation.