The long-term follow-up of women with gestational diabetes.

Four hundred and forty-seven women who had gestational diabetes have been retested at intervals from 1 to 12 years following diagnosis; 49 (11%) were found to be diabetic and 35 (7.8%) had impaired glucose tolerance using the WHO criteria. An abnormal glucose tolerance test in the puerperium and obesity at the time of retesting had significant associations with abnormal glucose tolerance at follow-up. However, the best predictive factor of the likelihood of the development of significant hyperglycaemia was the recurrence of gestational diabetes in a subsequent pregnancy, since 28% of these women were diabetic and a further 4% had impaired glucose tolerance at the time of follow-up. These findings indicate that the criteria used for the diagnosis of gestational diabetes at the Mercy Maternity Hospital, Melbourne (1-hour greater than or equal to 9 mmol/l together with a 2-hour greater than or equal to 7 mmol/l) are appropriate for an Australian population.