Gestational diabetes and subsequent development of NIDDM in aboriginal women of northwestern Ontario.

OBJECTIVES: To determine (1) the risk of development of non-insulin-dependent diabetes mellitus (NIDDM) in women with a previous history of gestational diabetes mellitus (GDM), (2) the average duration between diagnoses of GDM and NIDDM, (3) various modes of presentation, and (4) adequacy of follow-up post diagnosis of GDM.
METHODS: A retrospective chart review of women diagnosed with GDM in the Sioux Lookout Zone between 1985-1995. There were 4,211 pregnancies and 332 women with a diagnosis of GDM. Sixty-one charts were randomly selected. Both GDM and NIDDM were defined according to World Health Organization standards.
RESULTS: Seventy percent of the women with GDM went on to develop NIDDM. The average duration between diagnosis of GDM and diagnosis of NIDDM was three years. Greater than 70% of the women developed NIDDM within four years post diagnosis of GDM. The majority presented with asymptomatic hyperglycemia (88%); 3% presented with acidosis; 6% presented with symptoms of polydipsia and polyuria; and 3% presented with abnormal weight gain. Specific physician-requested follow-up after six weeks postpartum occurred in only 38% of the cases. However six-week follow-up occurred in 41%, a yearly follow-up occurred in 61% of the women, and 81% of the women had some sort of follow-up post diagnosis of GDM.
CONCLUSIONS: The risk of developing NIDDM after GDM is very high in Aboriginal women of the Sioux Lookout Zone. There is an urgent need for a structured follow-up program for this group of high-risk women. Furthermore, the offspring of these pregnancies should be a focus for follow-up and preventive programs.