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.