title: Changes in fetal cardiac geometry with gestation: implications for 3- and 4-dimensional fetal echocardiography.
abstract: OBJECTIVE
  Three- and 4-dimensional fetal echocardiography can be performed using novel algorithms. However, these algorithms assume that the spatial relationships among cardiac chambers and great vessels are constant throughout gestation. The objective of this study was to determine whether changes in fetal cardiac geometry occur during gestation.
  
  
  METHODS
  A cross-sectional study was conducted by reviewing 3- and 4-dimensional volume data sets from healthy fetuses obtained between 12 and 41 weeks of gestation. Volume data sets were examined using commercially available software. Parameters measured included angles between: (1) the ductal arch and fetal thoracic aorta; (2) the ductal arch and aortic arch; and (3) the left outflow tract and main pulmonary artery, as seen in the short axis of the heart. The mean angle from the left outflow tract to the short axis was calculated. Nonparametric statistics were used for analysis.
  
  
  RESULTS
  Eighty-five fetuses were included in the study. The angle between the ductal arch and the fetal thoracic aorta decreased with gestational age (Spearman rho coefficient: -0.39; P < .001). In contrast, the angle between the ductal arch and aortic arch, and the mean angle between the left outflow tract and the short axis of the heart increased with gestational age (Spearman rho coefficients: 0.45 and 0.40, respectively; P < .001).
  
  
  CONCLUSIONS
  (1) Changes in fetal cardiac geometry were shown with advancing gestational age. (2) Proposed algorithms for the examination of the fetal heart with 3-dimensional ultrasonography may need to be adapted to optimize visualization of the standard planes before 26 weeks of gestation.
authors: Perinatology Research Branch, National Institute of Child Health and Human Development, National Institutes of Health, Department of Health and Human Services, Bethesda, Maryland/Detroit, Michigan, USA.
authors: Jimmy
authors: J
authors: Espinoza
authors: Francesca
authors: F
authors: Gotsch
authors: Juan Pedro
authors: JP
authors: Kusanovic
authors: Luís F
authors: LF
authors: Gonçalves
authors: Wesley
authors: W
authors: Lee
authors: Sonia
authors: S
authors: Hassan
authors: Pooja
authors: P
authors: Mittal
authors: Mary Lou
authors: ML
authors: Schoen
authors: Roberto
authors: R
authors: Romero
mesh_terms: D000465:Algorithms; D001013:Aorta, Thoracic / Q000000981:diagnostic imaging / Q000196:embryology*; D003430:Cross-Sectional Studies; D004373:Ductus Arteriosus / Q000000981:diagnostic imaging / Q000196:embryology*; D019561:Echocardiography, Four-Dimensional; D019560:Echocardiography, Three-Dimensional; D005260:Female; D005318:Fetal Heart / Q000033:anatomy & histology* / Q000000981:diagnostic imaging; D005865:Gestational Age; D006801:Humans; D011247:Pregnancy; D016216:Ultrasonography, Prenatal / Q000379:methods*