Risk score for predicting primary cesarean delivery in women with gestational diabetes mellitus

BACKGROUND: Women with gestational diabetes mellitus (GDM) have a higher risk of cesarean delivery (CD) than glucose-tolerant women. The aim of this study was to develop and validate a risk score for predicting primary CD in women with GDM. METHODS: A risk score for predicting primary CD was developed using significant clinical features of 385 women who had a diagnosis of GDM and delivered at our institution between January 2011 and December 2014. The score was then tested for validity in another cohort of 448 individuals with GDM who delivered between January 2015 and December 2018. RESULTS: The risk score was developed using the features nulliparity, excess gestational weight gain, and insulin use. The scores that classified the pregnant women as low risk (0 points), intermediate risk (1–3 points), and high risk (≥ 4 points) were directly associated with the primary CD rates of the women in the development cohort: 14.7, 38.2 and 62.3%, respectively (P < 0.001). The model showed good calibration and acceptable discriminative power with a C statistic of 0.724 (95% confidence interval, 0.670–0.777). Similar results were observed in the validation cohort. CONCLUSION: A risk score using the features nulliparity, excess gestational weight gain, and insulin use can estimate the risk for primary CD in women with GDM.