Introduction
The most common metabolic disorder in pregnancy is hyperglycemia resulting from impaired blood glucose tolerance which is defined as either pregestational (PGDM) or gestational diabetes mellitus (GDM)1. Diabetes in pregnancy may cause many adverse perinatal outcomes including fetal macrosomia, stillbirth, neonatal hypoglycemia, preeclampsia and birth trauma2,3. The incidence of diabetes in pregnancy varies substantially across countries, ranging between 0.9% and 5.7% for PGDM and 1.8% and 25.4% for GDM4,5. Both type 2 PGDM and GDM could be diagnosed by various screening methods including fasting plasma glucose (FPG), HbA1c and oral glucose tolerance test (OGTT), but which one of them is the most successful for the diagnosis is still controversial.
Epicardial fat tissue is located between the visceral pericardium and myocardium and is usually distributed adjacent to the right ventricle6,7. Proinflammatory vasoactive peptides, tumor necrosis factor-α, interleukin-6 and anti-inflammatory substances (adiponectin, omentin, adrenomedullin) are released from epicardial fat tissue8,9. Furthermore, epicardial fat tissue contributes to myocardial energy production6. In recent years, measurement of epicardial fat thickness (EFT) in adults has been frequently used to detect insulin resistance10. It has been shown that there is a correlation between EFT and cholesterol, adiponectin and diastolic blood pressure11. Since EFT is not affected by changes in skin and muscle tissue, it is thought to be more reliable than some other measurements such as abdominal circumference12. However, conditions related to EFT are not clearly demonstrated in antenatal life as in non-pregnant adults. It has been proposed that increase in maternal EFT in pregnant women might be related to preeclampsia and vascular complications13,14.
Limited studies in the literature have shown that fetal EFT is higher in pregnant women with diabetes15-18. However, in these studies, the comparison of fetal EFT was conducted only in pregnancies with PGDM or GDM. Due to the methodology of previous studies, it could not be clarified whether there is a difference for fetal EFT values between pregnancies with PGDM and GDM. Therefore, the aim of this study is to identify whether fetal EFT differs in pregnant women with PGDM and GDM and also to correlate fetal EFT values with demographic parameters of diabetic pregnancies.