Published online by Cambridge University Press: 05 August 2012
The previous chapter and prior reviews demonstrate clear associations between maternal obesity and a range of pregnancy complications. Chief among these are gestational diabetes mellitus (GDM) and pre-eclampsia (PE), but other complications are also overrepresented including greater miscarriage risk, more cesarean sections, and even a heightened risk for intrauterine growth restriction (IUGR). The present chapter will discuss potential mechanisms linking obesity to GDM and PE. It will discuss postulated pathways, particularly for the obesity–PE link, and will show that many of these causal inferences are generally unfounded or exaggerated. The chapter will also provide a framework for future studies and describe potential strategies whereby the causal pathways may be explored.
Obesity and GDM
The strong epidemiological association between obesity and type 2 diabetes mellitus (T2DM) is well described . Similarly, as noted in the previous chapter, the same is also true for the obesity–GDM link. However, in recent years our understanding of the mechanisms linking obesity to diabetes in the non-pregnant arena has advanced considerably. A brief description of this highly relevant background is helpful for subsequent considerations of the pathways linking obesity to GDM.