Introduction
Gestational diabetes mellitus (GDM) refers to carbohydrate intolerance of varying degrees that occurs for the first time, during pregnancy [1]. The etiopathogenesis of the disease is still not fully understood. Inflammatory factors leading to insulin resistance and beta cell dysfunction triggered by placental hormones play an important role in the etiopathogenesis of the disease, along with obesity, genetic and environmental factors [2-5]. GDM remains a significant pregnancy complication causing adverse perinatal outcomes such as fetal macrosomia, birth trauma, birth polyhydramnios, respiratory distress syndrome, preterm birth, hypoglycemia, and operative delivery. [1,6,7]. It is well known that fetuses exposed to the effects of hyperinsulinemia and hyperglycemia during the intrauterine period may have poor outcomes, including the need for intensive care and low Apgar scores in the neonatal period. There is also an increased risk of long-term complications such as type 2 diabetes mellitus (DM), cardiovascular disease, obesity, and metabolic syndrome in these individuals [7-9].
Epicardial adipose tissue (EAT) is located between the visceral pericardium and the myocardium but is more prominent in the atrioventricular and interventricular grooves and the right ventricular sidewall [10,11]. It is derived from splanchnic mesoderm and shares a common embryological origin with omental and mesenteric fat [11,12]. In addition to adipose tissue, EAT also contains neuronal and nodular structures. It shows endocrine, immunological and inflammatory activities with its energy storage function. [13-15]. Moreover, an increase in epicardial fat thickness (EFT) has been shown to be associated with DM, cardiovascular disease and obesity [16-19]. Therefore, it is considered an important cardiometabolic marker in adults [20,21].
There are few studies that investigated the measurement of EFT in fetuses of mothers with GDM [22-25]. The need for markers that can help predict the occurrence of GDM and the increased risk of GDM-related perinatal complications remains one of the main topics of current studies. Because previous studies have shown that the increase in fetal adipose tissue in fetuses with GDM occurs most frequently in the 3rd trimester, we aimed to compare fetal EFT in the 3rd trimester in cases diagnosed with GDM with fetuses from healthy mothers [6,22]. To the best of our knowledge, this is the first paper to address the assessment of fetal EFT in patients with GDM and its relationship to neonatal outcomes and to determine the most appropriate cut-off value of EFT for predicting GDM in the 3rd trimester.