First trimester prognostic models for the development of gestational diabetes: A clinical impact analysis

OBJECTIVE: The aim of this study was to evaluate the clinical impact of first trimester prognostic models for the development of gestational diabetes mellitus (GDM). STUDY DESIGN: The clinical impact of prognostic models for GDM was analysed in a Dutch population-based prospective cohort study containing 3,723 pregnancies recruited before 14 weeks of pregnancy. Women with pre-existing diabetes mellitus of any type were excluded. In total 181 women (4.9%) developed GDM. In a previous study by our group, first trimester prognostic models for GDM were externally validated. In this study, the area under the receiveroperator- curve (AUC) was calculated for the five best performing refitted models. The effect of adding a first trimester random glucose measurement to the AUC of these models was calculated as well. The predictive accuracy of these models was compared with that of a model solely based on the presence of one or more pre-specified risk factors. According to Dutch guidelines these risk factors are BMI >30 kg/m2, history of GDM, first degree family member with diabetes mellitus, non-western ethnicity, presence of polycystic ovary syndrome or a history of unexplained intra-uterine fetal death. These women were tested for GDM with an oral glucose tolerance test at gestational age 24-28 weeks. RESULTS: The AUCs of the refitted first trimester prognostic models for GDM varied from 0.77 (95%CI 0.74-0.80) to 0.79 (95%CI 0.76- 0.82). The addition of the first trimester random glucose measurement improved all models, to a maximum AUC of 0.82 (95%CI 0.79-0.85) for the best performing model. In the current situation, standard care identifies 65% of all GDM cases by screening 28% of the population. Table 1 shows that this can be improved by the use of prognostic models for GDM. CONCLUSION: First trimester prognostic models for the development of GDM have a better predictive performance than prediction based on risk factors for GDM only, which offers opportunities for prevention and screening of GDM. (Table presented).