A Prediction Model of Gestational Diabetes Mellitus Based on OGTT in Early Pregnancy: A Prospective Cohort Study

Abstract Context Gestational diabetes mellitus (GDM) is a common obstetric complication. Although early intervention could prevent the development of GDM, there was no consensus on early identification for women at high risk of GDM. Objective To develop a reliable prediction model of GDM in early pregnancy. Methods In this prospective cohort study, between May 30, 2021, and August 13, 2022, a total of 721 women were included from Women’s Hospital, Zhejiang University School of Medicine. Participants were asked to complete an oral glucose tolerance test (OGTT) during gestational weeks 7 through 14 for early prediction of GDM, and at weeks 24 through 28 for GDM diagnosis. Using OGTT results and baseline characteristics, logistic regression analysis was used to construct the prediction model. Receiver operating characteristic (ROC) curve, Hosmer-Lemeshow test, decision clinical analysis, and a nomogram were used for model performances assessment and visualization. Internal and external validation was performed to testify the stability of this model. Results According to the International Association of Diabetes and Pregnancy Study Groups criteria in early OGTT, the mean (SD) age was 30.5 ± 3.7 years in low-risk participants and 31.0 ± 3.9 years in high-risk participants. The area under ROC curve (AUC) of the existing criteria at weeks 7 through 14 varied from 0.705 to 0.724. Based on maternal age, prepregnancy body mass index, and results of early OGTT, the AUC of our prediction model was 0.8720, which was validated by both internal (AUC 0.8541) and external (AUC 0.8241) confirmation. Conclusions The existing diagnostic criteria were unsatisfactory for early prediction of GDM. By combining early OGTT, we provided an effective prediction model of GDM in the first trimester.