After multivariate logistic regression analysis, pre-pregnancy BMI >30 (OR 1.86, 95% CI 1.42–2.45), family history of diabetes (OR 1.14, 95% CI 1.01–1.29), previous GDM (OR 1.81, 95% CI 1.36–2.43), hypothyroidism (OR 1.52, 95% CI 1.07–2.15), and ART pregnancy (OR 1.81, 95% CI 1.19–2.73) were identified as maternal variables significantly associated with the need of insulin therapy. This evidence concerns the gene INS and hypothyroidism.