[Occurrence of diabetes mellitus in women with prior gestational hyperglycemia].

Objective: To estimate the prevalence of glucose intolerance (diabetes mellitus and impaired glucose tolerance) in women who had their glucose tolerance evaluated and followed up during pregnancy.

Methods: Over the last 12 years since the index pregnancy, from a total of 3,113 pregnant women seen in an obstetrics clinic, 551 were randomly selected and proportionally to the number of women in each group. Of these, 529 could be evaluated and had been classified as follows: 250 in group IA (normal glucose tolerance); 120 in group IB (daily hyperglycemia); 72 in group IIA (abnormal oral glucose tolerance test); and 87 in group IIB (abnormal oral glucose tolerance test and daily hyperglycemia). The evaluation consisted of measuring fasting plasma glucose and when the results ranged between 6.1 and 6.9 mmol/L, patients were submitted to oral glucose tolerance test.

Results: Prevalence of diabetes mellitus was: IA, 1.6%; IB, 16.7%; IIA, 23.6%; and IIB, 44.8% (IA < [IB = IIA] < IIB; p<0.05). This difference between the groups remained the same for the eight years. Women in IA group were different from others regarding age, parity, and diabetes family history.

Conclusion: Hyperglycemia (high plasma glucose levels) and abnormal oral glucose tolerance test during pregnancy are equally effective in predicting the risk for developing maternal diabetes. When both tests are abnormal, this risk is much higher.