Infant
birth weight has increased in Ireland in recent years along with levels of
childhood overweight and
obesity. The present article reviews the current literature on maternal glycaemia and the role of the dietary glycaemic index (GI) and its impact on pregnancy outcomes. It is known that maternal weight and
weight gain significantly influence infant
birth weight.
Fetal macrosomia (
birth weight >4000 g) is associated with an increased risk of perinatal
trauma to both mother and infant. Furthermore, macrosomic infants have greater risk of being obese in childhood, adolescence and adulthood compared to normal-sized infants. There is evidence that there is a direct relationship between maternal
blood glucose levels during pregnancy and fetal growth and size at birth, even when maternal
blood glucose levels are within their normal range. Thus, maintaining
blood glucose concentrations within normal parameters during pregnancy may reduce the incidence of
fetal macrosomia. Maternal diet, and particularly its
carbohydrate (CHO) type and content, influences maternal
blood glucose concentrations. However, different CHO foods produce different glycaemic responses. The GI was conceived by Jenkins in 1981 as a method for assessing the glycaemic responses of different CHO. Data from clinical studies in healthy pregnant women have documented that consuming a low-GI diet during pregnancy reduces peaks in postprandial
glucose levels and normalises infant
birth weight. Pregnancy is a physiological condition where the GI may be of particular relevance as
glucose is the primary fuel for fetal growth.