Influence of maternal nutrition on genomic imprinting and fetal growth

To date, approximately 100 imprinted genes have been confirmed in mammals. Dysregulation of these genes, which are epigenetically regulated to maintain parent-of-origin monoallelic expression, has been associated with aberrant fetal growth - both over- and under-growth. As the imprinting-related epigenetic marks are set early in development and highly active in the placenta, imprinted genes are uniquely vulnerable to intrauterine environmental insults or nutrition imbalance that may alter these epigenetic control mechanisms. Herein we review emerging evidence from selected studies pointing to imprinted genes as potential mediators between in utero nutritional environment and birthweight. The review is organized by maternal dietary component - caloric intake, vitamins, and toxicants - and discusses the specific impacts of imprinted gene modifications on fetal birthweight. Although great variability between study populations, methods, and operationalization makes it difficult to draw gene-specific conclusions, the current literatures set the stage for future studies on the impact of the nutritional environment on modification of imprinted gene activity and subsequent fetal growth outcomes.