Abstract
Maternal diabetes during pregnancy, including gestational diabetes mellitus (GDM) and pregestational diabetes mellitus (PDM), has been linked to alterations in fetal development. This meta-analysis aimed to investigate the impact of maternal diabetes on fetal epicardial fat thickness (fEFT), measured via ultrasound-a potential marker of cardiometabolic risk. A systematic search of PubMed, Embase, and Web of Science was conducted to identify observational studies assessing fEFT in pregnant women with and without diabetes. A random-effects model was used to calculate the mean difference (MD) in fEFT between groups. Heterogeneity was evaluated using the I² statistic, and sensitivity, subgroup, and meta-regression analyses were performed to explore sources of variability. Data from 10 studies, comprising 12 datasets and 1303 participants, were pooled. Women with diabetes during pregnancy had significantly higher fEFT compared to those without diabetes (MD: 0.37 mm, 95% confidence interval [CI]: 0.26 to 0.49, P < 0.001), with moderate heterogeneity (I² = 69%). Sensitivity analyses, conducted by excluding one dataset at a time, confirmed the robustness of the findings (all P values < 0.05). Meta-regression revealed a positive correlation between gestational age (GA) at fEFT measurement and fEFT differences (coefficient = 0.040, P = 0.005), accounting for 83.2% of the heterogeneity. Subgroup analyses demonstrated consistent results across study designs, maternal diabetes types, and demographic factors but highlighted greater fEFT differences in studies where GA at fEFT measurement was >26 weeks. In conclusion, maternal diabetes during pregnancy is associated with increased fEFT, particularly in later gestation.