title: Main pulmonary artery cross-section ratio is low in fetuses with tetralogy of Fallot and ductus arteriosus-dependent pulmonary circulation.
abstract: OBJECTIVE
  This study aimed to determine fetal echocardiographic features of tetralogy of Fallot in association with postnatal outcomes.
  
  
  METHODS
  The Z-scores of the main and bilateral pulmonary arteries and the aorta were measured, and the following variables were calculated in 13 fetuses with tetralogy of Fallot: pulmonary artery-to-aorta ratio and main pulmonary artery cross-section ratio - the main pulmonary artery diameter squared divided by the sum of the diameter squared of the left and right pulmonary arteries. Fetuses were classified as having ductus arteriosus-dependent or ductus arteriosus-independent pulmonary circulation.
  
  
  RESULTS
  We included two infants with pulmonary atresia and six infants with ductus-dependent pulmonary circulation, who underwent systemic-to-pulmonary shunt surgeries at ⩽1 month of age. The Z-scores of the main pulmonary artery and the pulmonary artery-to-aorta ratio in fetuses with ductus-dependent pulmonary circulation were lesser than those in fetuses with ductus independence, but not significantly. The main pulmonary artery cross-section ratio in fetuses with ductus dependence was significantly lesser (0.65±0.44 versus 1.56±0.48, p<0.005). Besides, the flow of the ductus arteriosus was directed from the aorta to the pulmonary artery in the ductus arteriosus-dependent group during the fetal period.
  
  
  CONCLUSIONS
  The main pulmonary artery cross-section ratio was the most significant variable for predicting postnatal outcomes in fetuses with tetralogy of Fallot.
authors.affiliation: Department of Pediatric Cardiology,National Cerebral and Cardiovascular Center,Osaka,Japan.
authors.forename: Hironori
authors.initials: H
authors.lastname: Ebishima
authors.affiliation: Department of Pediatric Cardiology,National Cerebral and Cardiovascular Center,Osaka,Japan.
authors.forename: Kenichi
authors.initials: K
authors.lastname: Kurosaki
authors.affiliation: Department of Pediatric Cardiology,National Cerebral and Cardiovascular Center,Osaka,Japan.
authors.forename: Jun
authors.initials: J
authors.lastname: Yoshimatsu
authors.affiliation: Department of Pediatric Cardiology,National Cerebral and Cardiovascular Center,Osaka,Japan.
authors.forename: Isao
authors.initials: I
authors.lastname: Shiraishi
mesh_terms: D004373:Ductus Arteriosus / Q000000981:diagnostic imaging* / Q000196:embryology / Q000503:physiopathology; D004452:Echocardiography / Q000379:methods*; D005260:Female; D005315:Fetal Diseases / Q000175:diagnosis* / Q000503:physiopathology; D005865:Gestational Age; D006801:Humans; D007231:Infant, Newborn; D008297:Male; D011651:Pulmonary Artery / Q000000981:diagnostic imaging* / Q000196:embryology; D011652:Pulmonary Circulation / Q000502:physiology*; D011664:Pulmonary Valve / Q000000981:diagnostic imaging / Q000196:embryology / Q000503:physiopathology; D013771:Tetralogy of Fallot / Q000175:diagnosis* / Q000196:embryology / Q000503:physiopathology; D016216:Ultrasonography, Prenatal / Q000379:methods*
keywords: Tetralogy of Fallot; cross-sectional area; ductus arteriosus dependent; fetal echocardiography; pulmonary artery diameter