The quality of evidence is upgraded by very large magnitude of effect.
Use glucose tests for screening of women who have had gestational diabetes, if early diagnosis of type 2 diabetes is wanted.The recommendation is strong because of high cost-effectiveness (high number of positive screens relative to the number of people screened). The recommendation attaches a relatively high value on the potential benefit of early detection and treatment of type 2 diabetes.
In an another follow-up study of Mediterranea area , 70 GDM patients were evaluated one year after delivery. BMI, fasting and 1-h post-prandial plasma glucose, plasma glucose and insulinemia under OGTT were measured. 5 years after pregnancy 49 women were normal, 5 had developed type 1 diabetes and were not considered, 6 had developed IGT, and 10 type 2 diabetes. Variables predicting DM were BMI, fasting and post-prandial plasma glucose, plasma glucose at each point of the OGTT, and plasma insulin at 30min OGTT.
A meta-analysis identified 20 cohort studies in which women who had developed type 2 diabetes after GDM and included 675 455 women and 10 859 type 2 diabetic events. Women with GDM had an increased risk of developing DM compared with those who had a normoglycaemic pregnancy (RR 7.43, 95% CI 4.79-11.51). Although the largest study (n=659 164; 9502 cases of type 2 diabetes) had the largest RR (12.6, 95% CI 12.15—13.19), RRs were generally consistent among the subgroups assessed.
In a population-based, retrospective cohort study , women referred for an antepartum OGTT indicative of an abnormal 50-g glucose challenge test (GCT) (n = 15 381), but without GDM, were matched (for age, region, socioeconomic status, and year of delivery) with up to four other women without such referral (n = 61 237). The two cohorts were followed over a median 6.4 years for the development of diabetes. The rate of incident DM was 5.04 cases per 1000 person-years in the cohort of women who underwent an antepartum OGTT, compared with 1.74 cases per 1000 person-years in women without an OGTT. The hazard ratio for subsequent DM in women with abnormal (GCT) was 2.56 (95% CI 2.28 to 2.87, P < 0.0001).In an another retrospective cohort study , 185 416 pregnant women who had a GCT or OGTT were followed in Israel. Subsequent diagnosis of diabetes was ascertained by using an automated patient registry. A total of 11 270 subjects were diagnosed with GDM, comprising 6.07% of the cohort. During a total follow-up period of 1 049 334 person-years there were 1067 (16.9 per 1000 person-years) and 1125 (1.1 per 1000 person-years) diagnoses of postpartum DM among GDM and non-GDM women, respectively. The cumulative risk of incident diabetes in GDM patients with up to 10 years of follow-up was 15.7%, compared with 1% among the non-GDM population. GDM was associated with nearly an 8-fold higher risk of postpartum diabetes after adjusting for important confounders, such as socioeconomic status and BMI. Among women with a history of GDM, the number of abnormal OGTT values and use of insulin were associated with a substantially higher risk for developing DM.
Date of latest search: 2012-01-20