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Effects of Low-Glycaemic-Index Diet during Pregnancy on the Growth, Adiposity and Vascular Health of Offspring

Posted:  Thursday, September 15, 2016

Association between Low-Glycaemic-Index Diet during Pregnancy and Growth Outcomes of Offspring

Elevated blood glucose levels during pregnancy may contribute to adiposity, macrosomia and poor vascular health in the offspring. A longitudinal, pilot, prospective, follow-up study published in the American Journal of Clinical Nutrition investigated the effect of low-glycaemic-index (GI) diet during pregnancy on the growth, adiposity, and arterial wall thickness during infancy.

The trial included 59 mother-infant pairs who had been enrolled in a larger 2-arm randomised controlled trial that compared the effects of a low-GI diet with conventional high-fibre (HF) diet during pregnancy on perinatal outcomes. Length, weight and head circumference of infants born to these women were obtained from medical records every month for the first 6 months and then at 9 and 12 months of age. Infant adiposity was assessed at birth and at 3 months of age and aortic intima-media thickness (IMT) was assessed at 12 months of age.

Maternal dietary glycaemic index was lower among women in the low-GI group compared to those in the HF group. After birth, infant growth trajectories including head circumference and abdominal girth growth velocities were similar for both the groups. However, birth weight, birth length, weight for age z scores and length for age z scores were significantly higher among infants born to mothers in the HF group. Maternal GI at 36 weeks of gestation was not associated with the infant aortic IMT at 12 months of age. However, infants born to women in the low-GI group compared to those born to women in the HF group had significantly thinner aortic IMT.

The study demonstrated that in women at risk of gestational diabetes mellitus, a low-GI diet during pregnancy influences infant birth weight, length and arterial wall thickness during early childhood but not growth trajectory during the first year of life. Additional trials are required to authenticate whether these improvements in arterial wall thickness continue through childhood and during adulthood.

News source - Kizirian NV, Kong Y, Muirhead R, et al. Effects of a low-glycemic index diet during pregnancy on offspring growth, body composition, and vascular health: a pilot randomized controlled trial. Am J Clin Nutr. 2016 Apr; 103(4):1073–82.