Decreased flow‐mediated dilation in gestational diabetes in pregnancy and post‐partum. A systematic review and meta‐analysis

AIMS: Gestational diabetes mellitus (GDM) is a common medical complication during pregnancy. Endothelial dysfunction is considered an early step in the progression of atherosclerosis that may contribute to subclinical target organ damage. This meta-analysis aimed to systemically review the existing data regarding endothelial dysfunction between women with and without GDM during pregnancy and post-partum using flow-mediated dilation (FMD). MATERIALS AND METHODS: Eligible studies (cohort and observational) published until October 2021 were identified in the MEDLINE, Scopus, Cochrane Library database and grey literature sources were searched. RESULTS: The search yielded 2272 studies, of which 17 were fully reviewed and 12 studies (N = 740 pregnant women) were finally included. Pregnant women with GDM exhibited a significantly lower FMD compared to pregnant women without GDM (pooled mean difference -3.12; 95% CI -5.36 to -0.88). Moreover, in the immediate (1-6 months) post-partum period, women with previous GDM showed lower FMD compared to healthy women without GDM history (pooled mean difference -7.52; 95% CI -9.44 to -5.59), whereas FMD did not differ in the late post-partum period (more than 4 years). CONCLUSIONS: Flow-mediated dilation is decreased in women with GDM during pregnancy and in the immediate post-partum period, compared to women without GDM, indicating that the endothelial dysfunction noted during the pregnancy in those women persists in the immediate post-partum period too. CLINICAL TRIAL REGISTRATION: PROSPERO CRD42021283113 (www. CLINICALTRIALS: gov).