OP22.01: Prenatal diagnosis of sex chromosome aneuploidies before and after NIPT: an analysis of 30 years of population‐based data

Abstract

is no data on fetal thymus size in pregnancies complicated by maternal diabetes. Therefore, the objective of our study was to evaluate the influence of maternal diabetes on fetal thymus size. Methods: We retrospectively assessed 161 pregnancies of diabetic mothers and 161 uncomplicated pregnancies matched by gestational age (control group). Diabetic mothers were allocated to three different groups: 1. diet-controlled gestational diabetes, 2. Insulin-dependent gestational diabetes, and 3. pre-existing diabetes. The anteroposterior thymic and the intrathoracic mediastinal diameter were measured and we calculated the quotient as thymic-thoracic ratio (TT-ratio). Furthermore, we defined the thymus-head ration (TH-ratio) as the quotient of the anteroposterior thymic diameter and the circumference of the fetal head. Results: TT-and TH-ratios were significantly smaller in pregnancies with maternal diabetes (P < 0.001 and P < 0.001, respectively). In all three diabetes groups, both ratios were lower when compared to the control group (P < 0.001). Conclusions: TT-and TH-ratios were significantly smaller in pregnancies with maternal diabetes (P < 0.001 and P < 0.001, respectively). In all three diabetes groups, both ratios were lower when compared to the control group (P < 0.001).