Physiological, genetic, and epigenetic effects of maternal obesity during pregnancy on child health

Pre-pregnancy obesity and excessive gestational weight are modifiable risk factors, associated with adverse gestational and fetal outcomes, as well as adverse health outcomes in childhood. In this narrative review, we summarize main findings from epidemiological studies on the associations of maternal obesity and excessive weight gain during pregnancy with offspring outcomes in utero and in childhood. We expose the nutritional mechanisms involved in maternal obesity, as well as genetic and epigenetic effects underlying observed cardiometabolic outcomes. In particular, we explain how disentangling maternal and fetal genetic effects on birth weight, and report main findings on DNA methylation and other epigenetic modifications identified in the cord blood and placenta. Finally, we suggest some perspectives for future research to gain more insight in the biological processes involved in the fetal programming related to obesity.