A previous diagnosis of gestational diabetes (GDM) carries a lifetime risk of progression to type 2 diabetes of up to 60%. Identification of those women at higher risk of progression to diabetes allows the timely introduction of measures to delay or prevent diabetes onset. However, there is a large degree of variability in the literature with regard to the proportion of women with a history of GDM who go on to develop diabetes. Heterogeneity between cohorts with regard to diagnostic criteria used, duration of follow-up, and the characteristics of the study population limit the ability to make meaningful comparisons across studies. As the new International Association for Diabetes in Pregnancy Study Group criteria are increasingly adopted worldwide, the prevalence of GDM is set to increase by two-to three-fold. Here, we review the literature to examine the evolution of diagnostic criteria for GDM, the implications of changing criteria on the proportion of women with previous GDM progressing to diabetes, and how the use of different diagnostic criteria may influence the development of appropriate follow-up strategies.

Objective. To evaluate a 12-week group-based lifestyle intervention programme for women with prediabetes following gestational diabetes (GDM). Design. A two-group, mixed methods randomized controlled trial in which 50 women with a history of GDM and abnormal glucose tolerance postpartum were randomly assigned to intervention (n = 24) or wait control (n = 26) and postintervention qualitative interviews with participants. Main Outcome Measures. Modifiable biochemical, anthropometric, behavioural, and psychosocial risk factors associated with the development of type 2 diabetes. The primary outcome variable was the change in fasting plasma glucose (FPG) from study entry to one-year follow-up. Results. At one-year follow-up, the intervention group showed significant improvements over the wait control group on stress, diet self-efficacy, and quality of life. There was no evidence of an effect of the intervention on measures of biochemistry or anthropometry; the effect on one health behaviour, diet adherence, was close to significance. Conclusions. Prevention programmes must tackle the barriers to participation faced by this population; home-based interventions should be investigated. Strategies for promoting long-term health self-management need to be developed and tested.

Women with previous gestational diabetes (GDM) are a high-risk group for future development of diabetes, metabolic syndrome, and cardiovascular disease. The new International Association of Diabetes in Pregnancy Study Groups (IADPSG) criteria significantly increase the number of women diagnosed with GDM. The long-term metabolic outcome in these women is unknown. We set out to determine the prevalence of metabolic syndrome, using adult treatment panel-III criteria; and insulin resistance, using HOMA2-IR, in white European women with previous GDM. Using a cohort design, we invited women meeting IADPSG GDM criteria across four Irish antenatal centres between 2007 and 2010 to participate. Two hundred and sixty-five women with previous values meeting IADPSG criteria for GDM participated (44 % of the population eligible for participation). Mean age was 36.7 years (SD 5.0). These women were compared with a randomly selected control group of 378 women (mean age 37.6 years, SD 5.1) known to have normal glucose tolerance (NGT) in pregnancy during the same period. A total of 25.3 % of women with previous IADPSG-defined GDM met metabolic syndrome criteria, compared to 6.6 % of women with NGT [at 2.6 (SD 1.0) vs. 3.3 years (SD 0.7) post-partum]. The prevalence of HOMA2-IR >1.8 was higher in women with previous IADPSG-defined GDM (33.6 vs. 9.1 % with NGT, p < 0.001). Women with previous GDM by IADPSG criteria demonstrate a greater than threefold prevalence of metabolic syndrome compared to women with NGT in pregnancy. Efforts to prevent projected long-term consequences of this should focus on interventions both in the preconception and post-partum periods.

Objective: An increase in gestational diabetes mellitus (GDM) prevalence has been demonstrated across many countries with adoption of the International Association of the Diabetes and Pregnancy Study Groups (IADPSG) diagnostic criteria. Here, we determine the cumulative incidence of abnormal glucose tolerance among women with previous GDM, and identify clinical risk factors predicting this. Design: Two hundred and seventy women with previous IADPSG-defined GDM were prospectively followed up for 5 years (mean 2.6) post-index pregnancy, and compared with 388 women with normal glucose tolerance (NGT) in pregnancy. Methods: Cumulative incidence of abnormal glucose tolerance (using American Diabetes Association criteria for impaired fasting glucose, impaired glucose tolerance and diabetes) was determined using the Kaplan-Meier method of survival analysis. Cox regression models were constructed to test for factors predicting abnormal glucose tolerance. Results: Twenty-six percent of women with previous GDM had abnormal glucose tolerance vs 4% with NGT, with the log-rank test demonstrating significantly different survival curves (P < 0.001). Women meeting IADPSG, but not the World Health Organization (WHO) 1999 criteria, had a lower cumulative incidence than women meeting both sets of criteria, both in the early post-partum period (4.2% vs 21.7%, P < 0.001) and at longer-term follow-up (13.7% vs 32.6%, P < 0.001). Predictive factors were glucose levels on the pregnancy oral glucose tolerance test, family history of diabetes, gestational week at testing, and BMI at follow-up. Conclusions: The proportion of women developing abnormal glucose tolerance remains high among those with IADPSG-defined GDM. This demonstrates the need for continued close follow-up, although the optimal frequency and method needs further study.