The prevalence of gestational diabetes mellitus recurrence-effect of ethnicity and parity: a metaanalysis

Reports on the gestational diabetes mellitus (GDM) recurrence rate have been highly variable. Our objectives were to examine the possible causes of GDM recurrence rate variability and to obtain pooled estimates in subgroups. We have carried out a systematic review and metaanalysis based on the Metaanalysis Of Observational Studies in Epidemiology statement. We identified papers published from 1973 to September 2014. We identified papers using Medline (PubMed and Ovid), ClinicalTrials.gov and Google Scholar databases, and published references. We included only English-language, population-based studies that reported specified GDM criteria and GDM recurrence rate. A total of 18 eligible studies with 19,053 participants were identified. We used the Cochrane's Q test of heterogeneity to choose the model for estimating the pooled GDM recurrence rate. Metaregression was also used to explore the possible causes of variability between studies. The pooled GDM recurrence rate was 48% (95% confidence interval, 41-54%). A significant association between ethnicity and GDM recurrence rate was found (P=.02). Non-Hispanic whites had lower recurrence rate compared with other ethnicities (39% and 56%, respectively). Primiparous women had a lower recurrence rate compared with multiparous women (40% and 73%, respectively; P <.0001) No evidence for association between family history of diabetes and GDM recurrence was found. The overall GDM recurrence rate is high. Non-Hispanic whites and primiparous women have substantially lower GDM recurrence rates, which contributes to the variability between studies. Because no association between family history of diabetes and GDM recurrence was found, the large differences between ethnic groups may have also resulted from nongenetic factors. Thus, intervention programs could reduce the GDM recurrence rates.