A Review of Fetal Development in Pregnancies with Maternal Type 2 Diabetes Mellitus (T2DM)‐ Associated Hypothalamic‐Pituitary‐Adrenal (HPA) Axis Dysregulation: Exploring Links to Pregestational Prediabetes

A growing body of research has identified fetal risk factors associated with adult diseases that form the basis for the Developmental Origins of Health and Disease (DOHaD) hypothesis. This theory proposes a critical developmental period during which the fetus is highly susceptible to specific environmental influences that significantly impact health from short to long term. Maternal stress and T2DM during pregnancy are among these influences, likely leading to fetal overexposure to glucocorticoids and suggesting a shared pathway between maternal dysregulated HPA axis and fetal environmental insults. Studies demonstrate that prenatal glucocorticoid exposure alters fetal HPA axis function, affecting brain function, tissue glucocorticoid availability, and fetal growth in utero. These programmed changes, such as altered HPA axis function and reduced fetal growth, contribute to metabolic disorders persisting into adulthood. T2DM is preceded by a prediabetic state, often asymptomatic, which shares similar pathophysiological complications with T2DM, including HPA axis dysregulation observed in animals. Therefore, investigating prediabetes during pregnancy alongside maternal HPA axis function and its effects on fetal outcomes is crucial, as these areas remain understudied. This review aims to synthesize existing literature on pre-existing T2DM during pregnancy, its links to fetal programming via HPA axis changes, and possible links to pregestational prediabetes.