title: Comparative analysis of cerebrovascular resistance in fetuses with single-ventricle congenital heart disease.
abstract: OBJECTIVE
  We sought to determine whether the presence or absence of aortic obstruction impacts cerebrovascular resistance in fetuses with single-ventricle (SV) congenital heart disease (CHD).
  
  
  METHODS
  Pulsatility indices (PIs) were recorded for the middle cerebral artery (MCA) and the umbilical artery (UA) from 18 to 40 weeks' gestation in 59 fetuses (163 examinations) with SV-CHD with unobstructed aortic flow, yet decreased pulmonary flow, in 72 fetuses (170 examinations) with obstructed aortic flow and hypoplastic left heart syndrome (HLHS) and in 92 normal fetuses (92 examinations). The cerebral-to-placental resistance (CPR) was calculated as the MCA-PI/UA-PI. Z-scores were generated for the MCA-PI and the UA-PI in order to make comparisons independent of gestational age. Statistical analyses were performed using one-way ANOVA with post-hoc testing. Trends in these variables over the course of gestation were assessed using linear regression and univariate ANOVA.
  
  
  RESULTS
  The MCA-PI and the CPR were significantly lower in SV fetuses with aortic obstruction compared with SV fetuses with pulmonary obstruction and with normal fetuses. Moreover, the MCA-PI decreased significantly for SV fetuses with aortic obstruction over the course of gestation. In contrast, the MCA-PI was higher over the course of gestation in SV fetuses with pulmonary obstruction compared with normal fetuses.
  
  
  CONCLUSIONS
  In fetuses with SV-CHD, cerebrovascular resistance varies substantially between fetuses with and without aortic obstruction. Compared with normal fetuses, cerebrovascular resistance is decreased in SV fetuses with aortic obstruction, yet increased in SV fetuses with pulmonary obstruction. In fetuses with SV physiology, inherent differences in cerebral blood flow may underlie postnatal neurodevelopmental outcomes.
authors.affiliation: The Fetal Heart Program at Cardiac Center, Children's Hospital of Philadelphia, Philadelphia, PA 19104, USA. szwast@email.chop.edu
authors.forename: A
authors.initials: A
authors.lastname: Szwast
authors.forename: Z
authors.initials: Z
authors.lastname: Tian
authors.forename: M
authors.initials: M
authors.lastname: McCann
authors.forename: D
authors.initials: D
authors.lastname: Soffer
authors.forename: J
authors.initials: J
authors.lastname: Rychik
mesh_terms: D000704:Analysis of Variance; D001783:Blood Flow Velocity; D002560:Cerebrovascular Circulation; D002658:Developmental Disabilities / Q000000981:diagnostic imaging / Q000209:etiology / Q000503:physiopathology*; D005260:Female; D005865:Gestational Age; D006330:Heart Defects, Congenital / Q000150:complications / Q000000981:diagnostic imaging / Q000196:embryology / Q000503:physiopathology*; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D020768:Middle Cerebral Artery / Q000000981:diagnostic imaging / Q000196:embryology / Q000503:physiopathology*; D011247:Pregnancy; D011673:Pulsatile Flow; D016216:Ultrasonography, Prenatal; D014469:Umbilical Arteries / Q000000981:diagnostic imaging / Q000196:embryology / Q000503:physiopathology*; D014655:Vascular Resistance