Davidson AJF, Park AL, Berger H, et al. - Researchers conducted a population-based cohort study in Ontario, Canada, where there is universal healthcare in order to determine the link of an elevated preconception hemoglobin A1c (A1c) with severe maternal morbidity (SMM) or maternal death among women with and without known prepregnancy diabetes mellitus (DM). They performed an assessment of cohort including 31,225 women aged 16–50 years with a hospital live birth or stillbirth from 2007 to 2015, and who had an A1c measured within 90 days before conception; this cohort included 28,075 women (90%) without known prepregnancy DM. Among 682 births (2.2%), they observed SMM or death. After adjusting for maternal age, multifetal pregnancy, world region of origin, and tobacco/drug dependence, the relative risk of SMM or death was 1.16 per 0.5% rise in A1c. The adjusted relative risk of SMM or death was 3.25 among those without previously recognized prepregnancy diabetes and whose A1c was > 6.4%. Findings thus suggest correlation of an elevated preconception A1c with a higher risk of SMM or death among women without known diabetes, and below thresholds commonly used to diagnose DM. They emphasize the significance of a healthy diet and lifestyle before pregnancy, and call attention to the value of recognizing women with varying degrees of hyperglycemia before pregnancy.