Influence of carbohydrate-restricted versus calorie-restricted diets on rat placental glycogen

Abstract

Maternal blood glucose is the principle metabolic fuel for the developing placenta and fetus, and is the precursor for the large glycogen reserves that accumulate in the placenta and fetal liver during gestation. In this study we investigated whether maternal dietary glucose restriction would lead to lowered placental glycogen levels and compromised fetal growth. Pregnant rat dams were fed a carbohydrate-free (0% glucose) diet, which was compared to either a calorie-restricted pair fed or ad libitum control (62% glucose) group. Results demonstrated that a dietary glucose restriction produced statistically significant reductions in total placental glycogen and fetal weight but not placental size or glycogen concentration. It is suggested that restrictions in dietary glucose during the period of glycogen accumulation lower the maternal postprandial blood glucose supply sufficiently to reduce total placental glycogen levels. This reduction in total placental glycogen is associated with retarded fetal growth.