Key MessagesWe demonstrate the relationship between maternal diabetes and persistent pulmonary hypertension of newborns in a systematic review. The original studies were retrospective cohort or case-control studies, in which selection bias might exist. Variables (e.g. obesity, macrosomia, antidiabetic agents, antihypertensive agents, lifestyle changes) were often missing, which may influence outcomes.Keywords: diabetes mellitus persistent pulmonary hypertension of the newborn systematic review a b s t r a c t Objectives: Maternal diabetes mellitus (including pre-existing and gestational diabetes mellitus) is linked with adverse infant outcomes. However, the question of whether maternal diabetes increases the risk of persistent pulmonary hypertension of the newborn (PPHN) is unclear. Herein, we conducted a systematic review and meta-analysis to summarize clinical evidence to determine the association between maternal diabetes mellitus and PPHN. Methods: In this systematic review and meta-analysis, we systematically searched PubMed, Embase, Cochrane Library, Web of Science and Google Scholar to identify relevant studies according to predefined criteria. Data from selected studies were extracted, and meta-analysis was performed using fixed effects modelling. Results: In all, we included 7 unique studies with aggregated data on 2 million individuals and >5,000 cases of PPHN. Maternal diabetes was significantly associated with a higher risk of PPHN (risk ratio [RR], 1.37; 95% confidence interval [CI], 1.23 to 1.51). Both case-control and cohort studies exhibited that the presence of maternal diabetes increased the risk of PPHN (case-control: RR, 1.91; 95% CI, 1.02 to 2.79; cohort: RR, 1.36; 95% CI, 1.22 to 1.50). By omitting 1 study at a time, sensitivity analysis made sure that no individual study was entirely responsible for the combined results. Conclusions: Maternal diabetes was associated with increased risk of PPHN. For babies with refractory hypoxemia, with mothers with diabetes, PPHN should be taken into consideration in clinical practice. Ó 2019 The Author(s). Published on behalf of the Canadian Diabetes Association. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).Mots clés: diabète sucré hypertension pulmonaire persistante du nouveau-né revue systématique r é s u m é Objectifs : Le diabète sucré maternel (notamment le diabète sucré préexistant et le diabète sucré gestationnel) est lié à des issues défavorables chez le nourrisson. Toutefois, on ignore si le diabète maternel