Objectives: The size of cardiovascular structures in fetuses with congenital heart disease (CHD) is variable, and current reference structures used for comparative purposes are suboptimal: There are no known cardiovascular structures that are reliably normal in size. We sought to evaluate whether the aortic diameter at the diaphragmatic hiatus (ADDH) is affected in CHD.
Methods: The ADDH was evaluated by sonography in both study subjects (CHD group, n = 506) and age-matched normal controls (normal group, n = 506). The CHD group was divided into different subgroups according to evident anomalies in the cardiovascular system. ADDH differences between CHD subgroups and their controls were calculated with a paired Student's t-test. Possible sex differences were determined by an unpaired Student's t-test on the whole group.
Results: There were no significant differences in the ADDH between all CHD subgroups and age-matched controls (p > 0.05). No difference was found in the ADDH between female and male fetuses (p > 0.05).
Conclusion: The ADDH in fetuses with CHD is similar to that in controls. Hence, ratios between size of involved cardiovascular structures and ADDH may be a useful parameter for monitoring fetuses with CHD .