In the United States and Canada, literature about gestational diabetes mellitus (GDM) refers to insulin resistance and the probability that a woman will at some point in her life develop Type 2 diabetes. The Canadian Diabetes Association states, “Women who have had GDM are at increased risk of developing subsequent type 2 diabetes later in life” and make no mention of the increased risk of Type 1 diabetes. However, in Europe, educational materials almost always mention that GDM places a woman at risk for either Type 1 or Type 2 diabetes. The European medical community has long recognized that some women who have gestational diabetes are subsequently diagnosed with Type 1 diabetes. As reported in the August 1998 issue of Diabetes Forecast, in a German study 43 percent of women who developed gestational diabetes went on to have full-blown Type 1 diabetes. They were antibody positive, and they had not been diagnosed with diabetes prior to pregnancy. For example, the British Diabetes Association, Diabetes UK, states, “About five to ten percent of women with GDM develop Type 1 diabetes sometime in their life. These women have a slowly developing form of Type 1 that is ‘unmasked’ during pregnancy.” In the United States, autoimmune gestational diabetes is ignored by the American Diabetes Association and the Juvenile Diabetes Research Foundation. Yet if you ask women on TuDiabetes with Type 1 diabetes, many developed diabetes during pregnancy. Mary Tyler Moore, International Chair of JDRF, was diagnosed with Type 1 diabetes after a miscarriage at age 33. Why is there this disconnect--why do the U.S. and Canada ignore autoimmune gestational diabetes? It is important to identify a woman with autoimmune gestational diabetes, to prevent the severe maternal and fetal complications of Type 1 diabetes developing in pregnancy.
A recent article in the July 2007 issue of Diabetes Care indicated that autoimmune gestational diabetes (new onset Type 1 diabetes) accounts for about 10 percent of all Caucasian women diagnosed with gestational diabetes. In a recent study of Sardinian women (Reproductive Biology and Endocrinology, 2008), 40 percent of women with GDM were antibody positive (GAD, IAA, and/or IA-2) and had autoimmune gestational diabetes. (Sardinia has the second highest prevalence of Type 1 diabetes in the world, after Finland).
Sadly, in the U.S. and Canada many women with autoimmune gestational diabetes go for months if not years with wrong diagnoses, struggling to get appropriate treatment for the disease they have (Type 1 diabetes).
What are signs that you may have autoimmune gestational diabetes? If you are slim and require insulin during pregnancy to control your GDM, it is likely that you have autoimmune gestational diabetes. What can you do? Get antibody testing, which is relatively low cost and is a definitive test for Type 1 autoimmune diabetes.