Diabetes-related birth defects are preventable.(MASTER CLASS)

The World Health Organization judges the health of a country largely by its infant mortality rate. On this measure, the United States ranks 21st in the world. If we intend to improve the health of the nation, we must aggressively focus on reducing the two most significant contributors to infant mortality: prematurity and birth defects.

One of our efforts should focus on the fact that diabetes-related birth defects occur at a rate of 6%-10% among infants of diabetic mothers--a rate that is two to five times higher than the background rate of the general population.

These birth defects are often multiple and involve multiple organ systems, but the anomalies that usually are the most serious, disabling, and that may even be associated with death, include those affecting the central nervous system (neural tube defects or spina bifida of various types) and the cardiovascular system.

Hyperglycemia: A Teratogen

The causation of these anomalies has been studied in my laboratory and by many other groups around the world. It is clear, based on scientific findings, that hyperglycemia is a teratogen and causes direct injury to early embryonic tissue in the same way that any other teratogen, such as thalidomide or radiation, inflicts injury on a developing tissue.

The injurious effect of hyperglycemia is mediated by the induction or the production of free radicals and--simultaneously--by reductions in the body's natural glutathione antioxidant defense capacity. This results in excess free radicals which relentlessly target various tissues in the midst of early organogenesis. (See chart.)

With this knowledge of the biology of birth defect causation, we now know that by avoiding hyperglycemia during early pregnancy (the first 8 weeks), we can reduce the incidence of birth defects among diabetic offspring to mirror the incidence found within the nondiabetic population. This has been shown in clinical trials throughout the world.