Outcomes of singleton and twin pregnancies complicated by pre‐existing diabetes and gestational diabetes: A population‐based study in <scp>A</scp>lberta, <scp>C</scp>anada, 2005–11

Pre-existing diabetes confers higher risks than GDM. Diabetes is associated with adverse outcomes in singleton and twin pregnancies, and the increased risks are generally similar or less in twins, probably due to their higher "baseline" risks and closer clinical monitoring.