Adrenal gland size in fetuses with congenital heart disease

Objectives: The aim of this study was to compare the adrenal gland size of fetuses with congenital heart diseases (CHD) and normal fetuses. Methods: In this cross-sectional prospective study we measured the fetal adrenal gland size (total width, cortex width, medulla width, adrenal gland ratio of total width divided by medulla width) in 62 fetuses with CHD and 62 gestational-age-matched controls between 20 + 0 and 39 + 3 weeks of gestation. First, we clustered three CHD subgroups: CHD group_1 with a normal outflow tract (n=7), CHD group_2 with an altered outflow tract and anterograde flow in the ascending aorta (n=39) and CHD group_3 with an altered outflow tract and retrograde flow in the ascending aorta (n=16). In a second step, we summed up all CHD cases with outflow tract anomalies to CHD group_2 + 3 (n=55). Each group was compared to their matched controls. Results: Prenatally, fetuses affected by CHD with outflow tract alterations show an elevated adrenal gland ratio (total width/medulla width) compared to normal fetuses (p<0.001). This finding applies to both subgroups of outflow tract alterations with anterograde (p<0.001) and retrograde perfusion of the ascending aorta (p<0.001). Conclusions: Fetuses affected by CHD with an altered outflow tract show a relatively larger cortex of the adrenal gland compared to normal fetuses. The results of this study suggest that haemodynamic changes during fetal maturation cause an elevated metabolic stress level that may be responsible for an enlarged adrenal gland ratio.