Effect of maternal hypoglycaemia during gestation on materno-foetal nutrient transfer and embryo-foetal development: Evidence from experimental studies focused primarily on the rat.

Glucose is the major energy substrate during embryogenesis and the embryo is dependent on glucose from the maternal circulation to ensure normal metabolism and growth. The placenta plays a key role in this nutrient transfer in mammals, both during embryogenesis and after the development of the chorio-allantoic placental circulation. Maternal hypoglycaemia is accompanied by foetal hypoglycaemia and maternal counter-regulatory measures including a priority to keep nutrients in the maternal circulation by restricting their transfer to the foetus. Concomitantly, the foetus initiates its own counter-regulatory attempt to secure nutrients for its development and survival. Despite these measures, there is a general decrease in nutrient transfer to the foetus, which may have severe consequences for foetal development such as malformations and delayed skeletal development.