Trends and predictors of gestational diabetes mellitus in Chile

Objective To examine the temporal trends in gestational diabetes mellitus (GDM) prevalence in Chile, and to determine the main predictors of GDM. Methods A secondary analysis was conducted of all birth records at Hospital Dr. Sotero del Rio, Chile, from January 1, 2002, to December 31, 2015. We excluded those women with pre-existing type 2 diabetes, those with missing data, and those with unlikely data. GDM was defined as fasting glucose levels >5.55 mmol/L [>100 mg/dL] or >7.77 mmol/L [>140 mg/dL] 2 hours after glucose load in the oral glucose tolerance test. Potential predictors were selected based on prior research and ease of evaluation. Results From the original database of 100 758 records, 86 362 women were included in the final cohort. The mean GDM prevalence was 7.6% (95% CI [confidence interval] 7.5%-7.8%), increasing from 4.4% (95% CI 4.0%-4.9%) in 2002 to 13.0% (95% CI 12.0%-13.9%) in 2015. Age, education, marital status, parity, family history of type 2 diabetes, personal history of GDM, hypertension and pre-eclampsia, alcohol consumption, smoking, and pre-gestational nutritional status performed well in the prediction of GDM. Conclusion One out of eight Chilean pregnant women of medium- to low socio-economic status were found to develop GDM. We identified a set of easy-to-capture predictors in the primary health care system that may allow for the early identification of women at high-risk for the development of GDM.