1358-P: Point of Care OGTT for the Screening of Gestational Diabetes: A Feasible Proposal for Low-Resource Settings

Abstract

Due to the ubiquity of risk factors associated with gestational diabetes (GDM) in Mexican women and the low availability of the Oral Glucose Tolerance Test (OGTT), we compared the efficacy of two point of care (POC) models for GDM detection against the plasmatic 2hr OGTT-75gr in primary health care clinics in Mexico. We evaluated 328 pregnant women without previous diabetes diagnosis from a prospective cohort study “Cuido mi embarazo”; all of them were tested with the gold standard plasmatic 2hr OGTT-75gr for the diagnosis of GDM based on the ADA 2019 criteria. Simultaneously, we measured with a glucometer (ACCU-CHEK instant®) the glucose concentration either by capillary whole blood (172 measures) or from venous whole blood (156 measures). We evaluated the diagnostic accuracy by calculating the sensitivity, specificity, and ROC curve of each of the glucometer test results compared to the plasmatic test. For the first model, POC venous OGTT, the incidence of GDM was 41.66% compared to 7.05% of the plasmatic test. The ROC area under the curve for GDM prediction was 0.81 (95% CI 0.77-0.85), with a sensitivity of 100% and specificity of 62.8%. The low specificity is dependent on the fasting venous value of 64% since it was compared to 95% and 97% specificity of the 1hr and 2hr values, respectively. The second model, POC capillary OGTT, had an incidence of GDM of 30.23% compared to 8.13% of the plasmatic test. It had lower sensitivity (78.57%) and higher specificity (74.1%) compared to the first model, having an overall 0.76 (95% CI 0.65-0.88) ROC area under the curve for GDM prediction. We propose POC venous OGTT as a feasible diagnostic alternative for low resource settings where laboratory infrastructure is not available. Its positive bias could be beneficial since the treatment and control of early cases is related to better health outcomes for the moms and their babies. Further analysis is needed to improve GDM, POC screening interventions.