Detection of glucose intolerance in pregnancy

Current methods for the screening and diagnosis of glucose intolerance first discovered in pregnancy are reviewed and innovative approaches to the detection of metabolic disturbances in pregnancy are presented. Glucose intolerance first detected in pregnancy, termed gestational diabetes mellitus (GDM), is amongst the most significant risks of adverse fetal and maternal outcome. Normal pregnancy is characterized by both insulin resistance and pancreatic B cell compensation. In those pregnancies complicated by glucose intolerance reflected in hyperglycemia, insulin resistance appears to be heightened, both blood flow and transcapillary transport of insulin are compromised and insulin receptor and post receptor defects are exacerbated. The resulting hyperinsulinemia and hyperglycemia have, in turn, been associated with accumulated maternal fat deposition and fetal macrosomia. This cascade of events constitutes GDM or impaired glucose tolerance. The discovery of GDM is made through a process of screening and diagnosis, employing standardized oral glucose challenge tests. These tests were designed to identify those women at risk for subsequent development of non-insulin dependent diabetes mellitus. The current efficacy of glucose challenge tests has been questioned in light of increasing concern over their usefulness in detecting those women at risk for maternal and fetal complications of pregnancy. Alternative methods, including both the modification of the standardized tests, as well as the introduction of newer methodologies, such as capillary blood glucose monitoring, have been proposed. The implementation of newer approaches may result in improved detection of those women whose infants are at high risk for both metabolic and morphologic complications of persistent hyperglycemia in pregnancy.