Fetal Programming of Diabetes: Still So Much to Learn!

In the preinsulin era, pregnancy in a diabetic mother had a bleak outcome for both the mother and the baby. Availability of insulin and modern methods of treatment improved the survival of these babies, but they appear to be at increased risk of obesity and diabetes (1–3). Spread of the diabetes pandemic to the young means there is now a growing epidemic of gestational diabetes mellitus (GDM). This label encompasses all varieties of diabetes that happen to be diagnosed during pregnancy, but the majority of GDM cases have type 2 pathology and metabolic syndrome–like features. There is a tacit assumption that glucose intolerance may have arisen de novo, but this is unlikely. The majority of women have risk factors dating back before pregnancy, sometimes traceable to early life growth and development (4,5), and many continue to be diabetic after delivery or develop diabetes soon after (6). The degree of glucose intolerance qualifying for the diagnosis of GDM is still being debated, and there is little consideration of other metabolic parameters, such as lipids, in the diagnosis. There is a growing realization that even a mild change in the intrauterine environment influences the baby's prospects not only in the perinatal period but over the entire length of its life (7). These ideas are at the core of the emerging specialty of Developmental Origins of Health and Disease (DOHaD) (8). The process influencing long-term fetal outcomes is called fetal programming (9). The conceptus begins its life as a bag of genes that directs the development of a new individual. The new and important realization is that the intrauterine environment dictates how these genes function. A small change in this environment has the potential to permanentl y alter the working of genes and therefore the structure and function …