Prediction of gestational diabetes mellitus using early oral glucose tolerance test

Introduction Gestational Diabetes Mellitus (GDM) is defined as diabetes first detected at the second or third trimester of pregnancy, excluding preexisting diabetes. We aimed to build a predictive model of GDM using booking oral glucose tolerance test (OGTT) values. Materials and Methods Seventy-five healthy mothers who underwent 75g OGTT at 12-14 weeks and at 24-28 weeks were recruited. GDM was diagnosed at 28 weeks by cutoffs proposed by the Hyperglycemia and Adverse Pregnancy Outcomes study. Sensitivities and specificities for diagnosing GDM using different cut-offs for each of the three booking OGTT variables were measured. A series of multivariate binary logistic regression models were fitted using different combinations of the three booking OGTT variables. In-sample sensitivities and specificities for different cutoff probabilities of the models were calculated and Receiver Operating Characteristic (ROC) curves were constructed. The Area Under the Curve (AUC) of the ROC curve and the best cutoff value which maximized the sum of sensitivity and specificity of each model were computed. Results AUC of ROC curves for isolated fasting, 1 hour and 2 hour booking OGTT values for the prediction of GDM were 69.8%, 67.1% and 61.0% respectively. However, the logistic regression model with fasting and 1 hour booking OGTT values as predictors out-performed all other models with an AUC of 76.3%, in-sample sensitivity of 87.5% and a negative predictive value of 95.12%. Conclusions The future occurrence of GDM can be predicted utilizing a logistic model with fasting and 1 hour booking OGTT variables, which enables early identification and intervention. ### Competing Interest Statement The authors have declared no competing interest. ### Funding Statement The author(s) received no specific funding for this work ### Author Declarations I confirm all relevant ethical guidelines have been followed, and any necessary IRB and/or ethics committee approvals have been obtained. Not Applicable The details of the IRB/oversight body that provided approval or exemption for the research described are given below: Ethics review committee, Faculty of Medicine, University of Peradeniya I confirm that all necessary patient/participant consent has been obtained and the appropriate institutional forms have been archived, and that any patient/participant/sample identifiers included were not known to anyone (e.g., hospital staff, patients or participants themselves) outside the research group so cannot be used to identify individuals. Not Applicable I understand that all clinical trials and any other prospective interventional studies must be registered with an ICMJE-approved registry, such as ClinicalTrials.gov. I confirm that any such study reported in the manuscript has been registered and the trial registration ID is provided (note: if posting a prospective study registered retrospectively, please provide a statement in the trial ID field explaining why the study was not registered in advance). Not Applicable I have followed all appropriate research reporting guidelines and uploaded the relevant EQUATOR Network research reporting checklist(s) and other pertinent material as supplementary files, if applicable. Not Applicable Data will be held in a repository after publication.