Obesity and Lifespan Health--Importance of the Fetal Environment

Abstract

A marked increase in the frequency of obesity at the population level has resulted in an increasing number of obese women entering pregnancy. The increasing realization of the importance of the fetal environment in relation to chronic disease across the lifespan has focused attention on the role of maternal obesity in fetal development. Previous studies have demonstrated that obesity during adolescence and adulthood can be traced back to fetal and early childhood exposures. This review focuses on factors that contribute to early developmental events, such as epigenetic modifications, the potential for an increase in inflammatory burden, early developmental programming changes such as the variable development of white versus brown adipose tissue, and alterations in organ ontogeny. We hypothesize that these mechanisms promote an unfavorable fetal environment and can have a long-standing impact, with early manifestations of chronic disease that can result in an increased demand for future health care. In order to identify appropriate preventive measures, attention needs to be placed both on reducing maternal obesity as well as understanding the molecular, cellular, and epigenetic mechanisms that may be responsible for the prenatal onset of chronic disease.

Figure 1

Early programming can be initiated by a number of maternal and fetal factors that sets the stage for a lifetime of health or disease. BAT, brown adipose tissue; WAT, white adipose tissue.

Figure 2

In a mutually reinforcing way, early set points in the developmental process, such as the balance between white and brown adipose tissue, act together with exposures across the lifespan to enhance metabolic burden and immune system changes. In concert with adaptive mechanisms, these conditions underpin an increased likelihood of developing chronic disease in later life.