EP09.106: A case of dichorionic twin gestation concordant for atrioventricular septal defect

Congenital heart defects (CHDs) represent a heterogenous group of structural abnormalities generally caused by embryonic maldevelopment. The prevalence of CHD in twins is higher compared to singletons. However, concordant cardiac abnormalities affecting both twins are relatively uncommon, even in cases with monochorionic pregnancy. A 28-year-old woman with dichorionic twin pregnancy was examined at 13+2 weeks of gestation (w.g.) in our centre. An increased nuchal translucency, enlarged lymphatic jugular sacs, single umbilical artery and reversed A-wave in the ductus venosus was observed in twin A. Furthermore, a CHD was suspected in both twins. Fetal echocardiography performed at 15 w.g. revealed concordant atrioventricular septal defect (AVSD). The AVSD in twin A was unbalanced and was associated with coarctation of the aorta. In twin B, balanced AVSD with multiple muscular ventricular septal defects was observed. The ultrasound findings were confirmed by a pediatric cardiologist at 16 w.g. The non-invasive test (NIPT), opted by the patient, revealed a negative result. After an extensive counselling termination of pregnancy was performed. In conclusion, despite the relatively high prevalence of structural abnormalities observed in multiple gestations concordant CHD remains uncommon. Current evidence suggests that concordant CHD in twins is likely to be of similar type, as observed in our case. Please note: The publisher is not responsible for the content or functionality of any supporting information supplied by the authors. Any queries (other than missing content) should be directed to the corresponding author for the article.