Dilated ascending aorta in the fetus.

INTRODUCTION Prenatal recognition of dilated aortic root is extremely rare and there are significant challenges in counselling these patients. The primary aim of this case series is to describe the prevalence, associations and outcome of dilated ascending aorta diagnosed during fetal life. METHODS This is a retrospective cohort study from two tertiary fetal cardiology centres. Dilated ascending aorta was defined as gestation-specific standard deviation > 1.96 at some point during gestation. RESULTS Sixteen infants were live born and underwent postnatal echocardiography. Prenatally suspected bicuspid aortic valve (BAV) (n = 6) was confirmed in 5 cases (83%) postnatally. Thirteen children have been followed up for a period of minimum one year. No connective tissue disease was found. CONCLUSIONS Prenatal dilated ascending aorta is a rare finding (0.06%). It is associated with BAV in 37% of cases and extracardiac abnormalities in 15.7%. Nuchal translucency measurement was >3.5 in 13% of cases. Connective tissue disease was not diagnosed postnatally. This is the largest prenatal cohort with dilated ascending aorta and postnatal outcomes to date. We showed a postnatal persistence of ascending aortic dilatation in 43% of babies. In the absence of extra-cardiac abnormalities, medium term outcome appears good but postnatal surveillance of aortic dilation is required.