In this large, multinational study, glucose levels that were increased during pregnancy but were below levels diagnostic of diabetes were significantly associated with increased risks of birth weight above the 90th percentile and C-peptide levels above the 90th percentile, as well as with other adverse pregnancy outcomes. These results indicate the need to reconsider current thresholds for diagnosing and treating hyperglycemia during pregnancy.

This open-label trial compared insulin with metformin (with supplemental insulin if required) for the treatment of gestational diabetes mellitus. The rates of neonatal complications were similar in the two groups, and more women in the metformin group than in the insulin group reported that they would choose their assigned treatment again. These results provide support for the use of metformin as initial treatment for gestational diabetes in women who require pharmacologic therapy.

An electrocardiographic pattern of early repolarization (elevation of the QRS–ST junction) is generally believed to be benign. In this study, however, researchers found that among case subjects with idiopathic ventricular fibrillation, the prevalence of early repolarization was significantly increased, as compared with that among control subjects. These findings will lead to a reconsideration of the clinical significance of early repolarization.

A surgical procedure for cardiac sympathetic denervation successfully controlled recurrent polymorphic ventricular tachycardia in three patients with a heritable form of catecholaminergic polymorphic ventricular tachycardia.

This report describes three unrelated girls with an immunodeficiency disease associated with disseminated granulomas and compound heterozygous mutations in the RAG1 or RAG2 recombination activating genes. Unlike severe combined immunodeficiency disease with null mutations in RAG1 or RAG2, this immunodeficiency disorder did not present with severe infection in early childhood, probably because the RAG mutations allowed a low level of recombinase activity.