Perinatologist Corner - C.E.U/C.M.E. Modules
Diabetes In Pregnancy Series
Sponsored by The Indian Health Service Clinical Support Center
PART 1: Screening and Diagnosis
6. Classification
Case Continued
Mrs. Kanulie”s 3-hour glucose tolerance test showed:
FBS | 108 mg/dL |
1 hour | 198 mg/dL |
2 hour | 229 mg/dL |
3 hour | 129 mg/dL |
How is diabetes in pregnancy classified? The largest category of diabetes in pregnancy is gestational diabetes mellitus (GDM). Such women cannot be demonstrated to be diabetic when they are not pregnant and their glucose intolerance is usually rapidly reversed postpartum. Most such women are able to achieve good glucose control with medical nutrition therapy alone and are referred to as "class A-1".
If women with GDM are not able to establish euglycemia with diet, they are designated as "class A-2" and require pharmacotherapy. GDM may be considered to represent a patient "failing the metabolic stress test of pregnancy", the pathophysiology of which will be discussed below.
Women with pre-gestational diabetes usually have type II diabetes, and, as noted above, not all may have been diagnosed prior to their being seen for the current pregnancy. They are sometimes referred to as being "class B" diabetics.
Juvenile-onset, type I diabetes, is distinctly uncommon among our patients, and not a lot of time will be devoted to discussing it here. It is a much more challenging disorder to control during pregnancy, and both maternal and neonatal morbidity and mortality are significantly higher. Depending on the length of time these women have had their disease, and what target organ damage they manifest, they may also be assigned a White Classification "C, D, F, R, etc."
There is another entity currently being recognized more frequently, called "maturity-onset diabetes of youth" (MODY), an autosomal dominant disorder relatively common in Native Americans and Hispanics, usually diagnosed in late childhood or early adolescence, which has a clinical course typical of type II, not type I, diabetes. Most of these young women will have a strong family history and most, but not all, will have been diagnosed prior to pregnancy.